Criminal Justice Section  


Criminal Justice Magazine
Fall 2003
Volume 18 Number 3

Challenges of the Technological Revolution:

ABA Sets Standards for Electronic and Physical Surveillance

By Hon. Martin Marcus and Christopher Slobogin

Martin Marcus is a judge on the New York State Supreme Court, Bronx County, New York, and served as the reporter for the Standards on Electronic Surveillance. Christopher Slobogin is the Stephen C. O’Connell Professor of Law at the University of Florida Fredric G. Levin College of Law in Gainesville. He served as the reporter for the ABA’s Standards on Technologically-Assisted Physical Surveillance.

Editor’s Note: Parts of this article are taken from the commentaries to the ABA Standards for Electronic Surveillance and the Standards for Technologically-Assisted Physical Surveillance, as well as from the article "Technologically-Assisted Physical Surveillance: The American Bar Association’s Tentative Draft Standards" by Christopher Slobogin (10 Harvard J.L. & Tech. 383 (1997)), and from an address by Martin Marcus titled "Reconsidering the ABA’s Criminal Justice Standards on Electronic Surveillance" given at the Fortunoff Colloquium, Center for Research in Crime and Justice of the New York University School of Law, on Feb. 22, 2000. To order copies of the Standards, go to the Criminal Justice Section Web site at

In the 35 years since the American Bar Association first promulgated Standards governing government wiretapping and bugging of telephone communications, surveillance technology has evolved into an array of tools that the drafters of the Standards would have thought science fiction. Advanced methods of monitoring oral, telephonic, and computer communications have joined space-age visual surveillance techniques in law enforcement’s arsenal. Noting these changes, the ABA recognized as far back as the mid-1990s a need for new Standards that would be useful to lawyers, legislators, judges, and law enforcement officials dealing with the dual concerns of crime fighting and privacy rights in an age of widespread technological advancement.

In 1995, the Criminal Justice Standards Committee of the ABA Criminal Justice Section appointed the Task Force on Technology and Law Enforcement to suggest revisions to the second edition of the ABA’s Electronic Surveillance Standards, and to develop guidelines for other types of technological surveillance. Comprised of prosecutors, criminal defense attorneys, law enforcement officials, judges, privacy experts, and academics, the task force consulted scores of organizations, ranging from national law enforcement agencies and local police departments to technology experts and advocates for individual privacy. Over a five-year period, it identified and assessed the primary constitutional and policy issues raised when technology is used to solve and prevent crime. The result is two sets of new Standards: The Standards on Technologically-Assisted Physical Surveillance and the Standards on Electronic Surveillance (third edition).

The Standards on Technologically-Assisted Physical Surveillance provide recommendations concerning government use of physical surveillance technology such as video, tracking devices, magnification and illumination devices, and detection devices that can discern items through opaque surfaces. The ABA House of Delegates adopted those Standards in August 1998. The Standards on Electronic Surveillance contain recommendations governing interception of communications over phones, computers, and other communication methods. They were adopted by the ABA House of Delegates in February 2000.

Together, these Standards represent a concerted effort to deal with the challenges to privacy and security posed by advances in technological surveillance techniques. They recognize that new technology can be a valuable law enforcement tool, but only when used under carefully circumscribed circumstances. Although neither set of Standards purports to govern investigation of domestic terrorism by foreign agents, the principles found in them are particularly pertinent in the wake of September 11, 2001, with the increased need to regulate and provide for the investigation of terrorist activity.

What follows is a description of some of the important provisions of both sets of Standards.

Communications surveillance

The ABA has had Standards governing electronic surveillance of private communications since 1968. Those Standards preceded the substantially similar provisions of Title III of the 1968 Omnibus Crime Control and Safe Streets Act, 18 U.S.C. §§ 2510, et seq., which governed "wiretapping"—the interception of "wire," or telephonic communications—and "bugging"—the interception of "oral," or face-to-face communications. The rules announced in the ABA Standards and in Title III, and the principles that underlay them, made sense in the world of electronic communications and electronic surveillance of the times. In the ensuing decades, however, extraordinary technological changes have taken place, and ever more rapid change has become the norm. Given these developments, the Standards (which were substantially unaltered in their revision in 1978), and Title III (even as updated by the Electronic Communications Privacy Act of 1986 [ECPA]), no longer made sense. The new Standards suggest how to reconfigure the rules of electronic surveillance to adapt to the consequences and demands of present and future technology.

In 1968, virtually the only device for electronically transmitted communication was the telephone. In those days, the handset of the telephone was always connected to the base of the phone by a cord, and the base was always physically connected to a telephone line, which transmitted—by wire or cable—the voice of the person using that telephone to the person at the other end of the call. When law enforcement officers obtained an order permitting them to intercept telephone conversations over a particular telephone, the officers went to the telephone company for "pair and cable" information that directed them to a location where they could find an "appearance" of the line over which calls to and from that phone were transmitted. That location—say at a point along a wire on a telephone pole or in a telephone box in a basement—was usually within a mile of the location of the telephone, and often much closer. The phone was tapped by physically connecting the intercepting line to the tapped line at the location of the appearance, and the "plant"—the place where the officers sat and intercepted the conversations—was located somewhere very near where that connection was made. The officers intercepted the conversations in real time: They overheard and recorded them at the same time the words of the parties to the conversations were spoken, transmitted, and heard at the other end.

In Katz v. United States, 389 U.S. 347 (1967), the Supreme Court held that the Fourth Amendment protects people and not places, and that, when a telephone call is intercepted, the interception is a search governed by the Fourth Amendment, whether or not a physical trespass is necessary to install the device used to intercept the conversation. In Berger v. New York, 388 U.S. 41 (1967), the Court laid out what the Fourth Amendment requires for electronic surveillance: not only a court order and probable cause to support it, but also a particular description of the crimes, people, and communications subject to interception, and reasonable limitations on the scope of the authorized search. When Congress drafted Title III and when the ABA drafted its original Standards, questions that arose in applying these constitutional requirements to electronic surveillance, and in establishing other nonconstitutional rules, were answered in the context of the prevailing technology described above.

Changes in technology have complicated the regulation of electronic surveillance and rendered obsolete some of the definitions and concepts by which that regulation was achieved: first, in determining whether some kinds of private communications deserve more protection than others; second, in determining the geographical jurisdiction of courts that issue electronic surveillance orders; third, in limiting the scope of the search authorized by an order through a procedure known as minimization; and fourth, in protecting the integrity of the records made of the intercepted communications.

What’s protected and how much?

The first question, whether some forms of private electronic communications deserve more protection than others, simply never arose in 1968, since the only kind of technologically transmitted communications deemed worthy of special protection were telephonic ones. So when Congress enacted Title III, it decided to regulate only the "interception" of telephonic and face-to-face communications, and limited the term "intercept" to mean the "aural acquisition" of the contents of communications, that is, to the interception of the human voice. (18 U.S.C. § 2510(4).) In 1986, however, when ECPA became law, the technology had changed sufficiently to cause Congress to amend the definition of "intercept" to mean "the aural or other acquisition of the contents of communications," recognizing that communications without the human voice are also deserving of special protection. ( Id. (emphasis added).) But the question was, how much protection? Congress’s answer was, a lot, but not the same degree of protection that Title III gave communications that include the human voice.

Thus, when Congress adopted ECPA, it provided to electronic communications most of the protections given to aural ones, including all of the constitutional protections set forth in Berger, and many of the nonconstitutional protections given in Title III. For example, in Title III, Congress established a policy that electronic surveillance should be used only as a last resort. (18 U.S.C. § 2518(1)(c).) Because of this policy, one of the most important distinctions between an ordinary search warrant and an electronic surveillance order is that an application for electronic surveillance must demonstrate "necessity," or what is also more colorfully but less accurately called "exhaustion." To satisfy this requirement, an application must show that other means of investigation have been tried and have failed to achieve the objectives of the investigation, or are not likely to succeed, or are too dangerous to employ. In ECPA, Congress decided that applications authorizing the interception of electronic communications, like aural ones, must satisfy this requirement.

There are, however, three respects in which Congress afforded electronic communications less protection than aural ones. The first relates to who may apply for an electronic surveillance order. In order to centralize federal policy concerning electronic surveillance of aural communications, and to make those responsible for it easily identifiable and accountable, Title III permits only the U.S. attorney general and a very limited number of high ranking U.S. Department of Justice (DOJ) officials to apply for a warrant authorizing the interception of aural communications. For the interception of electronic communications, in contrast, the authority to apply for a court order is much more dispersed, and includes any United States attorney, or any authorized assistant U.S. attorney. ( Compare 8 U.S.C. § 2516(1) and (3).) Although the DOJ, on its own volition, continues to restrict such applications to only those officials who may apply for orders authorizing the interception of aural communications, the distinction in the law remains.

Second, although Congress limited aural surveillance to the investigation of certain kinds of crimes, excluding primarily consensual sex crimes, it provided that a federal warrant authorizing the interception of electronic communications may be issued in connection with an investigation of "any Federal felony." ( Compare 18 U.S.C. § 2516(1) and (3).)

Third, Title III includes a specific provision requiring the suppression of aural communications that have been unlawfully obtained. (18 U.S.C. § 2518(10)(a).) The Supreme Court has made clear that this suppression remedy attaches not only to constitutional violations, but to significant statutory ones as well. ( See United States v. Giordano, 416 U.S. 505, 527 (1974).) When ECPA was enacted, however, Congress intentionally avoided including provision for a motion to suppress electronic communications. So, under federal law, while constitutional violations remain a ground for suppression of electronic communications, statutory violations—even important ones like the failure to establish the exhaustion of conventional means of investigation—are probably not.

From today’s perspective, it is hard to imagine why Congress would treat aural and electronic communications differently, and the legislative history is remarkably silent on this issue. Looking back, however, it was probably because electronic communications were then used primarily by governments, businesses and universities, and Congress may have viewed electronic communications—like telexes—as business records deserving a lesser expectation of privacy. This rationale, however, relies on a vision of impersonal communications between large organizations, and fails to take account of the privacy interest of the individual members or employees of those organizations. It also fails to take account of the privacy interests of customers and clients of those large organizations, whose communications may reveal much about their personal affairs, including their financial condition and their intellectual, political, and recreational interests. Moreover, whatever validity this business rationale once had has been further undercut by the use we now all make of e-mail, pagers, and fax machines for entirely private purposes. Increasingly, individuals use electronic communications interchangeably with aural ones, trading the value of hearing the human voice for the convenience and savings, and sometimes the anonymity, attendant to communicating electronically. Given this new reality, there is no justification for giving greater protection to a communication that includes the human voice over one that is purely "electronic" but is otherwise identical in content.

Another argument sometimes made for distinguishing between aural and electronic communications is that electronic communications are more vulnerable to interception than telephone calls. However, new technology, including the increasing use of encryption, has reduced that vulnerability substantially. In any case, whether it is easier to intercept a private e-mail than a telephone call is beside the point. In 1986, when Congress explicitly extended the protections of Title III to the use of cellular telephones, it determined that when a person used a cordless telephone a law enforcement officer could intercept, without a court order, the radio portion of that person’s telephone call as it was transmitted from the base to the handset. The theory was that such communications were too easily subject to interception by anyone close by, merely by using a radio, and thus it was not reasonable for a person who used a cordless phone to expect that his or her communications would not be overheard by others. In 1994, however, Congress abandoned this exception to Title III, and extended its protections to cordless as well as cellular and conventional telephones. In part, this reflected changes in technology that made it harder to intercept cordless communications, but that was not the only reason. With the benefit of more experience, it must have become obvious that people expected their privacy to be respected on a cordless phone like on any other phone, and that this expectation was reasonable, even if a conversation on a cordless telephone remained to some degree vulnerable to a neighbor’s snooping.

Thus, there is no justification for broadly dispersing the authority to authorize applications for the interception of electronic communications, for increasing the list of crimes for which electronic communications may be intercepted, and for precluding suppression for the violation of a statute regulating the interception of electronic communications, no matter how central the statute is to the overall legislative scheme. Accordingly, the third edition of the Standards explicitly conclude that "[p]rivate communications should be afforded the same level of protection whether they are spoken in person or transmitted by technological means, and if by technological means, whether or not the communications include the human voice." (Standard 2–3.1(a)(iv).) And consistent with that principle, the Standards protect both aural and electronic private communications, and extend the same degree of protection—constitutional and statutory—to both.

Jurisdictional issues

A second question Title III and the Standards answered in the context of the prevailing technology was the appropriate geographical jurisdiction of a court for issuing an electronic surveillance order. Given that technology, the answer was relatively simple. Jurisdiction might focus on the location of the phone that was the subject of the order, since a judge in a particular jurisdiction would arguably be most concerned for the privacy rights of the people within that jurisdiction. Alternatively, jurisdiction might focus on the place where the order was to be executed, that is, the place where the officers were actually intercepting the communications, since it made sense for a judge to issue an order that would be carried out within the judge’s own jurisdiction. In 1967 and 1968, when all telephones were stationary, or at least no more mobile than a very long cord could make them, a law enforcement officer who had the address to which the telephone being tapped was listed knew the place where at least one end of the communication was occurring. And because the communications were to be intercepted at a location nearby, both purposes could be achieved—that is, the judge could both direct the activities of officers and protect the privacy rights of persons within the judge’s jurisdiction—by basing a court’s authority to issue an order on the place where the order was to be executed, which is exactly what Title III did. (18 U.S.C. § 2518(3).) ( See United States v. Rodriguez, 968 F.2d 130, 136 (2d Cir. 1992).)

The logic of Title III’s solution to geographical jurisdiction collapsed, however, when the technology dramatically changed. First, the "how" and "where" communications are being sent and received have altered. For example, with portable cellular telephones or a personal digital assistant (PDA), the "place" from which the communication is being transmitted can change from one jurisdiction to another, even as the communication is occurring. And law enforcement officers who are executing an electronic surveillance order may not even know the location of the parties whose communication they are intercepting at the time of the interception.

Second, technology has altered how and where communications are intercepted. Although ordinary telephonic communications can be and often are intercepted at or near the location of an appearance and within a short distance of the tapped telephone, for many years a device called a "slave" has been used to route intercepted calls from or to a particular phone line to another line. Using a slave, law enforcement officers can, within financial constraints, intercept telephonic communications virtually anywhere, even at great distances from the tapped telephone. No less significantly, communications sent to pagers, cellular telephones, and similar devices, which are transmitted by radio or microwave over a broad geographical area, are not intercepted by attaching a device to the appearance of a telephone line, but by the use of a clone of the phone or the pager, which a law enforcement officer can use anywhere in that broadcast area. That area may now extend well beyond the confines of city and county to cover a state, a region, the country, even the globe.

Given these developments, tying jurisdiction to the place of execution means that a prosecutor often picks the jurisdiction in which the order is issued by simply choosing where the order will be executed. And a court may authorize officers to intercept communications within its jurisdiction, despite the absence of any geographical nexus between the jurisdiction and the communications, or between the jurisdiction and the crime under investigation. When faced with these issues, courts interpreting Title III and similar state provisions tying jurisdiction to the place of execution have permitted electronic surveillance orders to be issued in any jurisdiction where technology permits the communications to be intercepted. While this solution has the virtue of simplicity, it no longer is supported by logic or policy. Accordingly, the Standards require that the court issuing an order be one that has geographical jurisdiction over the crime for which the electronic surveillance is authorized. The advantage is that the facts of the crime under investigation, rather than arbitrary and sometimes limitless possibilities of technology, determine the focus. Moreover, given that any resulting prosecution will most likely take place in the jurisdiction in which the order is executed, both the prosecutor and the issuing judge will know that the legality of the issuance of the order and of its execution will likely be litigated within that same jurisdiction.

Thus, the Standards provide that a federal judge can issue an order authorizing the interception of communications "regardless of where those communications are occurring" so long as two requirements are met: first, that the "communications are to be intercepted within the United States"; and second, that the offense is being committed "within the territorial jurisdiction of the court." (Standard 2–4.7(a).) Pursuant to this standard, a federal judge in the Southern District of New York could authorize federal officers in Los Angeles to intercept communications occurring in Tokyo, so long as the surveillance related to a crime in Manhattan or elsewhere in the Southern District.

To some extent, the Standards treat orders issued by state court judges similarly, but they also recognize and resolve other problems not applicable to federal orders. Generally, they permit a state court judge with geographical jurisdiction over an offense to issue an order authorizing the interception of communications relating to that offense "regardless of where those communications are occurring," so long as the "communications are to be intercepted within the state." (Standard 2–4.7(b)(i).) In general, a New York State judge could authorize the interception of communications relating to a New York crime, anywhere in the State of New York, so long as technology allowed for such interception within the state. And this is true even if the communications were occurring over a cellular phone or pager that was sometimes used in New York, but at other times in New Jersey, California, or Tokyo.

To what degree, however, should one state respect the electronic surveillance policies of another? What should happen, for example, if the communications to be intercepted are between two people that a state or local law enforcement officer knows are in another state? Under those circumstances, should that other state have something to say about whether those communications may be intercepted in New York? If law enforcement authorities in New York have probable cause to believe that communications relating to a New York crime are occurring between two people in New Jersey—a state that has a much more restrictive electronic surveillance statute—should the New York authorities be able to intercept those communications merely because one of the parties is using a cellular telephone or a pager, and technology permits their communications to be intercepted in New York? The Standards resolve this problem by providing that a state court judge should be permitted to issue an order authorizing the interception of communications occurring between or among parties known to be outside the state only pursuant to an interstate compact permitting such interceptions. (Standard 2–4.7(b)(iii).) By deciding to join, or not join, in such a compact, a state with a more restrictive electronic surveillance statute, or one that prohibited electronic surveillance entirely, could determine whether or not communications known to be occurring entirely within its borders should be subject to knowing interception by a foreign state or local law enforcement officer.

What happens if law enforcement officers have probable cause to believe communications relating to a New York crime are occurring outside of New York, but those communications can only be intercepted outside the state? Many states permit the issuance of a conventional search warrant authorizing the search and seizure of property that is evidence of a crime committed in another state. Similarly, the standards would permit a judge of a state in which communications relating to an out-of-state crime can be intercepted to authorize their interception, "regardless of where those communications are occurring," so long as two requirements are met: first, that the interception take place "within the territorial jurisdiction of the court in which the judge is sitting"; and second, that "the law of the state in which the judge sits permits the judge to issue an order." (Standard 2–4.7(b)(ii).) Thus, if these two conditions are met, a California judge may authorize state or local authorities in California to intercept communications relating to a New York crime, on behalf of a New York prosecutor.

Of course, in all of these situations, if the foreign state has not adopted the necessary legislation or entered into the interstate compact, some communications will inevitably be beyond the reach of a state’s court order. However, another option will usually exist: The state or local prosecutor can enter into a joint investigation with the U.S. attorney’s office, which can seek a federal order to which these geographical constraints and comity issues will not apply.


Minimization is a third issue resolved by federal law and the previous standards in the context of no longer prevailing technology. Minimization is the obligation placed upon law enforcement officers executing an electronic surveillance order to make a good faith attempt to limit their interceptions to those conversations that are relevant to the criminal activity they are authorized to investigate. ( See 18 U.S.C. § 2518(5).) It is a major part of the law’s response to Berger’s demand that the search authorized by an electronic surveillance order be reasonable. The primary way by which intercepting officers traditionally satisfied the minimization requirement was by listening to conversations as they were being intercepted, and to stop intercepting for a period of time if they determined that a particular conversation, or a particular part of a conversation, was not pertinent to the crime that was the subject of the investigation. That determination could be made based on a number of factors, including the telephone number being called, or the one from which the call was being received; and, once the call went through, on who the parties were, and on what the actual content of their conversation was. To the extent that the officers recorded everything that they intercepted, they created a record that, later on, a defense attorney could use to challenge, and a suppression court could use to determine, whether the minimization requirement had been sufficiently honored. To the extent that the officers did not intercept nonpertinent communications, the privacy of those communications was preserved because no one ever overheard or recorded them.

Given the difficulties of sorting out, in real time, the pertinent telephone calls from nonpertinent ones, the executing officers necessarily enjoyed broad discretion in intercepting communications whose significance was ambiguous. As a result, it sometimes was—and still is—difficult to enforce meaningfully the requirement that the intercepting officers minimize the interception of nonpertinent communications. But however difficult aural communications may be to minimize in real time, for electronic communications real time minimization is impossible. Electronic communications, such as e-mails and faxes, arrive at their destination more or less all at once. Even if transmission takes as long as several minutes, by the time it is intercepted, it usually must be intercepted in its entirety—without the ability to first determine who the sender or receiver is, where it’s being sent from, or what the subject or even one part of the communication is. Such communications must be minimized, if at all, only after they are intercepted.

Title III, as amended by ECPA, permits such after-the-fact minimization when communications are coded or in a foreign language. (18 U.S.C. § 2518(5).) Oddly enough, it does not explicitly authorize after-the-fact minimization of electronic communications. The congressional history for ECPA, however, makes clear that Congress understood the problem and meant to permit after-the-fact minimization when contemporaneous minimization is not possible. The Standards do more. Unlike federal law, they explicitly authorize the use of after-the-fact minimization, but permit it only when the technological means by which the communications are transmitted do not permit contemporaneous minimization. (Standard 2–4.9.)

Moreover, although it proved impossible to specify in all cases exactly how to accomplish minimization after-the-fact, the Standards try to say something meaningful about how it should be done. First, they provide that "as soon as practicable after the communications are intercepted, a law enforcement officer who is familiar with the investigation of the offense for which the electronic surveillance is authorized, or an individual acting under the supervision of such a law enforcement officer, [should accomplish satisfaction of the minimization requirement] as soon as practicable after the communications are intercepted." (Standard 2–4.9(a)(i).) That officer would then disseminate to other investigators only the pertinent communications, and would not disclose the nonpertinent ones to anyone else. (Standard 2–4.9(a)(v).)

Second, the Standards provide that "to the extent reasonable and possible, that minimization [should be] accomplished in a manner designed to protect the privacy interests of the parties to the communications to the same extent as properly conducted contemporaneous minimization, had [it] been possible." (Standard 2–4.9(a)(ii).) Obviously this statement is more of an exhortation than a specification as to what should be done, but it does make clear that one approach to after-the-fact minimization should be rejected. When technology requires that every communication be intercepted, and intercepted in its entirety, the argument could be made that the minimizing officer should read every word of every communication, and then cull out the pertinent from the nonpertinent ones. After all, when minimization is conducted in real time, it is inevitable, not only that many non-pertinent communications will be intercepted, but also that some pertinent communications will not. When minimization is accomplished after the fact, however, that need not happen. In such cases, the privacy of the parties has already been invaded to the extent that all of their communications have been intercepted in their entirety. So why not permit the minimizing officer to read all of the communications, in their entirety, to be sure that no pertinent ones are lost, secure in the knowledge that the nonpertinent ones will not be further disclosed? The Standards reject this approach, recognizing that a respect for privacy requires making a distinction between a communication being intercepted by a machine, and one being read or heard by a person, and that reasonableness requires that when no limitation can be placed upon what communications the machine seizes, some attempt should be made to limit which, and which part, of the seized communications should be read or heard by that person.

What methods can and should be used to search for the pertinent communications will, of course, vary with their type and with the prevailing technology. With faxes and e-mail, for example, and with other kinds of electronic documents, it may be possible to determine the parties to a communication before examining the content. However, because pertinency can rarely be determined based solely on the identity of the parties, and because the parties to an electronic communication may falsely identify themselves, or not identify themselves at all, a search of the content of the communications will most often be required. Even then, however, it may be possible to use technology to conduct the search in a way that maintains a continuing concern for privacy.

For example, if a law enforcement officer is sufficiently familiar with the nature of the investigation and the probable nature of the criminal communications, a simple word processing program, or perhaps something more sophisticated, may permit the minimizing officer to search for names, phrases, or words in each communication without the officer having to read its text, and the officer may then limit the review of the text to only those communications in which those names, phrases, or words appear. As with conventional minimization, the use of coded and cryptic terms may make this a less satisfactory alternative and may require the officer to read more communications than otherwise, but, as with conventional minimization, the use of such terms by the subjects of the surveillance will justify the greater intrusion on privacy. Moreover, if a search for particular terms is not productive, since all the communications have been intercepted and still exist, it will be possible for the officer to try a different search using other names, phrases, and words, and yet still not see or hear the content of the communications. Unlike with conventional minimization, the officer can have more than one opportunity to determine whether particular communications are likely pertinent, and can take advantage of those additional opportunities without intruding significantly further on privacy.

What should happen to the records of those communications the minimizing officer determines are not pertinent? One approach—the one most analogous to real-time minimization, and the one arguably most respectful to privacy—would be to immediately destroy them. The Standards reject that approach, and instead require that the officer preserve an original record of all the communications made as they were intercepted and before they were minimized. (Standard 2–4.9(a)(iv).) The primary reason to preserve these communications is that they might prove exculpatory to the defendant. Thus, the Standards provide that when after-the-fact minimization is employed, any communications the minimizing officer determined were not pertinent should be disclosed to the defendant, Standard 2–6.2(e)(i), and, if the defendant intends to offer any of those communications in evidence at trial, to the prosecuting attorney as well. (Standard 2–6.2(e)(iii).) In order to protect the privacy of third parties, however, the Standards require that any such disclosure be subject to a protective order issued by the court. (Standard 2–6.2(e)(iv).)

Protecting communications records

Yet another question resolved in the context of once prevailing but now outdated technology was how to protect the integrity of the tape recordings that were the best evidence of the contents of intercepted communications. When such communications were recorded on reel-to-reel tapes, as they were in the late 1960s, and later on cassette tapes, the tapes could be brought "immediately" after the authorized period of electronic surveillance—and, in theory, before they could be subjected to tampering—to the judge who had issued the electronic surveillance order. The judge could then "seal" them in a very simple and nontechnological way, by dating and initialing masking tape, or evidence tape, wrapped around the recording, or around a box in which the recording had been placed. Applying the sealing requirement, 18 U.S.C. § 2518(8)(a), has had its particular frustrations. From the defendant’s point of view, judicial sealing did too little to protect a tape recording’s integrity, since the obligation to seal did not arise until the end of the electronic surveillance, leaving, at least in theory, considerable time for tampering, particularly with those recordings made early in the surveillance. And from the prosecution’s point of view, the sealing requirement was too harsh, as when it was interpreted to require suppression of tape recordings that were sealed a day late, even if expert testimony could establish that they had not been subjected to tampering.

When Title III and the earlier Standards talked about sealing "recordings," they reflected the technology of the time, which captured the human voice only on audio- or videotape. Now aural communications can also be recorded on drives and disks, both floppy and hard, and compact and not. And, of course, electronic communications, without the human voice, are also recorded on such drives and disks. The new Standards recognize this new technology by abandoning the term "recording" in favor of the more technologically neutral term "record," and they take advantage of this technology by requiring that in order "[t]o maximize the reliability of evidence obtained through the interception of private communications, a record of the contents of the [intercepted] communications . . . should, whenever technologically possible, be made and preserved in a manner designed to protect its integrity." (Standard 2–3.1(c)(iv).)

The question remains whether it still makes any sense to require the "sealing" of such records, and to suppress them for untimely sealing. There was a surprising unanimity among the members of the ABA task force that suppressing tapes for violating the requirement that they be brought to a judge for "immediate" sealing—no matter how the term "immediate" is defined—is an arbitrary remedy that, in the end, fails to do much of anything to ensure the integrity of the records. The Standards do not impose suppression as a mandatory per se remedy for untimely sealing, and in fact make no mention of the word "sealing" at all. Instead, the Standards recognize that technology can be more effective than a piece of tape, and so require that "[t]o the extent possible and reasonable given the form of the communications and the available technology, the equipment and techniques used to make the records should . . . either protect an original record from editing or other alteration, or disclose whether that record has been edited or altered." (Standard 2–4.14(b).) Technology that creates disks with read-only memory are but one example of what is possible for this purpose. Although the defendant at trial can challenge the integrity of the records, the issue for the court and jury will be the same as it is for the integrity of any other kind of record, to be decided based on the evidence, and not on whether an arbitrary and meaningless "sealing" deadline was met.

Subjects left unaddressed

While the third edition of the Electronic Surveillance Standards represents an attempt to comprehensively address the issues raised by the technological revolution of the last three decades, there are a few areas it left for another day. First, even though the revised Standards govern the interception of the contents of private communications, they do not regulate the capture of transactional data relating to such communications; for example, in the case of a telephone call: the number called, the number called from, and the subscribers to those numbers. As in its previous editions, the Standards do not consider under what circumstances law enforcement should be permitted to use pen register or trap and trace devices. Similarly, they do not consider when law enforcement should have access to the routing information that directs and accompanies electronic mail as it is transmitted from the sender to the recipient. These subjects were excluded from the Standards, not because they were deemed unworthy of consideration, but rather because access to such transactional data raises issues more appropriately the subject of a separate set of standards that make comprehensive recommendations for "transactional surveillance." Such standards could consider not only access to transactional data relating to communications, but real-time surveillance of other kinds of transactions; for example, the payment of electronic tolls by a car traveling along a highway. Because the issues are closely related, such standards could also consider the appropriate rules for governmental access to the growing variety of other forms of transactional data (e.g., credit card records, frequent flier program records, and photographs of vehicles leaving airports.)

A second subject not addressed by the revised Standards is encryption. The Standards announce that "law enforcement agencies should, in appropriate cases and under appropriate regulation, have the legal authority and the technological means to conduct electronic surveillance." (Standard 2–3.1(b)(i).) Because powerful programs for encrypting communications are now readily available on the general market, the question arises whether, when law enforcement receives judicial authority to intercept communications that are encrypted, that authority should include the power to demand from the communications provider the technical means to decrypt the communications. Proponents for such authority fear that without it, the legitimate, court-authorized goals of a law enforcement investigation can be easily thwarted. Opponents argue that encryption has become a powerful tool for privacy at a time when communications are increasingly vulnerable to illegal interception. Despite extended discussion, no consensus emerged within the task force, which will continue to evolve with further developments in the technology of encryption and decryption and with further consideration in Congress and elsewhere.

Third, the Standards abandon the minimal attempt made in the first and second editions to regulate electronic surveillance relating to foreign intelligence activities, a subject drastically affected not only by technological change, but also by the events of September 11, 2001, and its aftermath. Even before September 11, it was decided that determining whether the authorized purposes for foreign intelligence surveillance should be expanded to make them consistent with the Foreign Intelligence Surveillance Act (FISA), 50 U.S.C. § 1801, was a matter beyond the expertise of the task force. Considering both that question and whether the ABA should make more specific recommendations about how the president and Congress should set standards for and supervise foreign intelligence surveillance is more properly the subject of a separate inquiry. In any case, the Standards could not have directly addressed the changes made in Title III and the Electronic Communications Privacy Act by the USA PATRIOT Act of 2001, the antiterrorism law enacted in response to the destruction of the World Trade Center and the attack on the Pentagon, since the Act became law after the Standards were adopted by the ABA House of Delegates. Given present events, however, it is obvious that the courts have two important and pressing tasks: finding the appropriate boundaries between conventional electronic surveillance under Title III and foreign intelligence electronic surveillance under FISA, and developing under those statutes and the USA PATRIOT Act the rules pursuant to which information gathered in the execution of FISA orders may be used in criminal prosecutions.

Conclusion to electronic standards

The third edition of the Standards on Electronic Surveillance are a product of more than three years of effort by experts in the field of criminal procedure in general, and electronic surveillance in particular. They reflect an attempt to establish, in a field revolutionized by ever more complex and intrusive technology, the delicate balance between the privacy rights of individuals, on the one hand, and the legitimate needs of law enforcement and the legitimate rights of communication service providers, on the other. They also recognize that technology is a double-edged sword, which, depending upon how it is wielded, can undermine or enhance important privacy interests, legitimate law enforcement needs, and the rights of those who are investigated and prosecuted by the use of electronic surveillance. Of course, the revolution in communications is far from over—it may well be just beginning. The challenge in drafting the third edition of the Standards was to develop principles and rules, and to find approaches and solutions, that do not merely reflect current communications and surveillance technology, but that anticipate, and, indeed, break free from the constraints of developing technology. Time will tell how well they have succeeded in meeting this challenge.

Technologically-assisted physical surveillance

Like communications surveillance technology, surveillance technology that allows observation of physical activities and conditions is vastly improved over that of a few decades ago. The technology can be divided into five categories: video surveillance, tracking, illumination, and telescopic and detection devices. In each area, developments have been dramatic.

Video technology has significantly improved in the past three decades. With the advent of wide-angle and pinhole lenses, night vision equipment, and supermagnification capacity, video surveillance allows viewing of home interiors, workplaces, and public thoroughfares at all times of the day and night. Cameras can be placed in picture frames, briefcases, pens, suit lapels, and teddy bears, allowing covert observation in virtually any circumstances. They also can be used, overtly and conspicuously, to surveil private establishments and public places. Furthermore, any surveillance by camera can be recorded, permitting a permanent record of activities within the camera’s range. Digitization of video provides sharper picture, easier storage, faster location of desired images, and the capacity to transmit intercepts in real time to squad cars and other officers in the field.

Tracking devices also come in many forms. One of the simplest is the beeper that emits a signal that can be traced electronically and can be placed in virtually any vehicle or item. Other tracking devices under development or already in use include radar that can monitor vehicles over the horizon; bi-static sensor devices that either passively pick up various types of emissions (e.g., from a cellular phone) or rely on an active sonar-like capacity; and tagging systems that use a projectile launcher to attach a beeper to a fleeing vehicle. Also of relevance here are efforts to construct "intelligent transportation systems," which involve fitting every vehicle in a given transportation network with radio units that transmit to a base station. Developed principally as a way of controlling traffic patterns, these systems also provide a way of tracking individual vehicles, or of discovering where they were located at a previous point in time.

Telescopic and illumination devices—binoculars, telescopes, flashlights, and spotlights, for example—have been available for more than century. Today, however, science has provided would-be viewers with significantly greater capabilities to overcome obstacles created by distance and darkness. Compact night-vision equipment using infrared technology allows covert observation of any nighttime activity, while map-making and satellite cameras are able to focus on objects a few feet across from thousands of feet in the air. Illumination and telescopic capacity can also be combined in one instrument (and, as noted above, video recording capacity can be added as well).

Finally, detection systems have been developed that include a wide range of devices using X-rays, heat radiation sensors, holographic radar scanners, and other technologies. Simple metal detectors have been augmented by devices that can be held in the hand and discern shapes and sizes of items underneath a person’s clothing and even behind walls; some of these devices also reveal anatomical details. Other mechanisms have been developed for detecting hidden explosives and the "heat waste" that might signal use of klieg lights or furnaces connected with growth or manufacture of contraband.

These examples merely begin to describe the variety of physical surveillance technology. The types and capabilities of observational devices that can be used to assist in criminal investigations will continue to emerge and expand. One of the first issues confronted by the task force was whether this constant innovation would moot any efforts at regulation. But the task force and the Standards Committee concluded that a delay in devising a regulatory scheme in this area would be ill advised, for a number of reasons.

First, technologically-assisted physical surveillance has become routine practice in some law enforcement contexts. A number of government agencies now commonly use video surveillance, tracking, illumination and magnification devices, and some even make prolific use of detection devices. Those developments suggest that a regulatory framework, even one that will require revision in the near future, is needed.

Such a framework has not been forthcoming from the courts, which suggests a second reason for standards governing technologically-assisted physical surveillance. Traditional legal doctrine does not necessarily answer many of the novel questions raised by such surveillance. The constitutional provision most relevant to regulation of physical surveillance is, of course, the Fourth Amendment, which bans unreasonable searches and seizures and requires that warrants authorizing searches and seizures be based on probable cause. As currently interpreted by the courts, this constitutional guarantee does not apply to some types of surveillance techniques that nonetheless ought to be subject to some controls. For example, given its public nature, use of video cameras to scan the streets probably does not trigger the warrant or probable cause protections of the Fourth Amendment, yet most would agree that such surveillance should be subject to some sort of regulation. Equally important issues concerning execution and accountability, such as how long surveillance records may be kept and whether the public ought to be apprised of how often surveillance technology is used, have traditionally fallen outside the ambit of the Fourth Amendment as construed by the courts.

A final reason for issuing standards governing physical surveillance despite the rapid pace of technological development is to prompt nonjudicial lawmaking in the area. Many of the questions left unaddressed or addressed inconsistently by the courts could be handled more satisfactorily by rules issued by other law-making bodies, such as legislatures or law enforcement agencies. Yet, in contrast to electronic surveillance of communications, technologically-assisted physical surveillance has never been the subject of comprehensive legislative oversight. Neither the ABA Standards on Electronic Surveillance nor Title III and its various successors at the federal level regulate technological enhancement of this type of investigation. State and local lawmaking bodies have also largely avoided the issue, and police departments generally lack rules on the subject. It is hoped that the Standards will trigger more of this type of rulemaking activity, or at least provide a model for it.

General description of the Standards

The Standards seek neither to expand nor contract those situations that require a warrant or a particular level of cause under the Fourth Amendment, nor are they intended to add to or detract from the constitutionally mandated remedies for violations of that Amendment. At the same time, the Standards recognize that there are areas in which Fourth Amendment principles alone may not provide adequate protection for the privacy and related interests that are implicated by the use of new technologies for criminal investigations. In these areas, they recognize that it may be desirable to enact, by legislative or administrative rule, protections that go beyond those recognized in current Fourth Amendment case law.

There are six Standards governing physical surveillance technology. The first Standard sets out general principles. The second contains definitions. The final four Standards govern the specific surveillance techniques mentioned earlier: video surveillance, tracking devices, illumination and telescopic devices (treated together), and detection devices.

Standard 2–9.1, the general principles Standard, attempts to accomplish several goals. First, it lays the substantive groundwork for the specific Standards that follow. (Standard 2–9.1(c).) It also sets forth general principles concerning the execution of surveillance, Standard 2–9.1(d), the role to be played by different governmental entities in regulating surveillance, Standard 2–9.1(e), and the means by which accountability can be established. On the latter score, it calls for "administrative rules which ensure that the information necessary for such accountability exists," internal sanctions for violations of the rules, periodic review of "the scope and effectiveness of technologically-assisted physical surveillance," and dissemination to the public of "information about the type or types of surveillance being used and the frequency of their use." (Standard 2–9.1(f).)

Standard 2–9.2 provides definitions for the four remaining Standards, 2–9.3 through 2–9.6. As noted, these final four Standards deal with use of video surveillance, tracking devices, illumination and magnification devices, and detection devices, in that order. Applying the factors outlined in the general principles Standard, they describe the showing required for various uses of these technologies. In general, they track Fourth Amendment law in requiring probable cause for surveillance of areas associated with a reasonable expectation of privacy (and a warrant in non-exigent situations), except in a few well-defined situations related to unusual hazard, where a showing either of reasonable suspicion or a compelling state interest suffices. When surveillance is of a nonprivate area or activity, the Standards generally require that use of the surveillance be reasonably likely to achieve a legitimate law enforcement objective, a term defined below.

As with the discussion of the Standards on communications surveillance, further elaboration of the Standards on technologically-assisted physical surveillance in this article will focus on just a few of the more important subject areas. One of the most significant issues raised by technologically-assisted physical surveillance is how the law should distinguish between "private" and "nonprivate" areas and, assuming such a distinction can be made, whether surveillance of nonprivate areas should be regulated at all. A second crucial issue is the extent to which post-surveillance privacy should be maintained through rules governing notice of the surveillance and disclosure and maintenance of surveillance records. Finally, the special problems that are raised by law enforcement use of detection devices, which do not merely enhance surveillance capability, but permit viewing of conditions that could not possibly be seen with the naked eye from a lawful vantage point, are worth discussing in some detail.

Justification requirements

Law enforcement can clearly benefit from technology that allows safer, more accurate, less costly, and more efficient surveillance. Just as clearly, such surveillance can infringe on important individual interests such as privacy. Crucial to implementation of the Standards is a means of determining which locations and activities are or are not associated with a "reasonable expectation of privacy" protected by the Fourth Amendment. Surveillance aimed at a protected area must be justified, usually at the probable cause level, and often requires a warrant as well. Surveillance of other areas need not be justified at all, at least as far as the Fourth Amendment is concerned.

The latter point requires some elaboration. The Supreme Court has made clear that activities that take place in public are normally not accorded Fourth Amendment protection because one assumes the risk that activities conducted in public will be viewed by casual observers. ( Knotts v. United States, 460 U.S. 276 (1983).) More recently, it stated in Kyllo v. United States, 533 U.S. 27 (2001), that even activities that take place in the home and other private places may lose Fourth Amendment protection if they can be seen with the naked eye from a public vantage point, or if they can be seen with technology that merely replicates what such naked eye viewing could observe. ( Id. at 34, 40.) Kyllo also indicated that the Fourth Amendment does not protect even those activities and conditions that cannot be seen with the naked eye if they can be viewed from a lawful vantage point using technology that is "in general public use." ( Id.)

Although the Standards were promulgated before Kyllo was decided, they are consistent with the law as described above. Rather than adopting a rigid definition of privacy, they employ a multifactor test taken from Supreme Court decisions and those in the lower courts. Thus, whether probable cause is required under the Standards depends on the nature of the place or activity to be surveilled, the care taken to enhance privacy, the lawfulness of the vantage point, the availability and sophistication of the technology used, the extent to which such use is minimized, and whether the surveillance is overt or covert. (Standard 2–9.1(c)(ii).) At one point, the task force considered recommending a less imprecise test that would have provided full protection for any activity that takes place in the home or similar location. But that approach, it was decided, would not only have gone beyond the Fourth Amendment, but would have failed to reflect the protean nature of privacy. Thus, for instance, the person who engages in activity before a picture window situated a few feet from the public sidewalk is not entitled either to Fourth Amendment protection or to "probable cause" protection under the Standards.

However, the Standards do not merely mimic Fourth Amendment case law. They state at the outset that technologically-assisted physical surveillance should be regulated not only when it diminishes privacy, but also when it diminishes "freedom of speech, association and travel, and the openness of society." (Standard 2–9.1(b).) Consistent with that view, the Standards recommend, as noted earlier, that even surveillance of public activities should be limited to situations in which it is "reasonably likely to achieve a legitimate law enforcement objective." This language is defined to require "articulable reasons" for concluding that the surveillance will assist in detecting, investigating, deterring, or preventing crime. (Standard 2–9.2(d).) This new regulatory concept has two essential elements. First, surveillance must be for a legitimate law enforcement end, not for harassment or political purposes. Second, the way in which the surveillance will achieve a law enforcement end must be "articulable." Thus, under this Standard, video or telescopic surveillance of people who go into and leave a suspected crack house would be permissible, and video or telescopic surveillance of people in a high-crime area probably would be as well, but surveillance of people in a low-crime area on the off-chance crime might be detected would be more difficult to sustain. Aside from overt, short-term use of illumination and telescopic devices, see Standard 2–9.5(b)(i), all technologically-assisted physical surveillance of nonprivate areas must meet the reasonable likelihood test.

The Standards regulate surveillance of nonprivate areas in other ways as well. Nonexigent covert video surveillance of public areas must be approved by a "supervisory officer," see Standard 2–9.3(c), defined as a midlevel law enforcement officer who has "participated in specialized training on surveillance techniques and applicable guidelines." (Standard 2–9.2(g).) Overt video surveillance of public areas that is "long-term" must be approved by a "politically accountable public official or the relevant politically accountable governmental authority." (Standard 2–9.3(b)(i).) Furthermore, in the latter situation, the "public to be affected by the surveillance" must be notified of the intended location and general capability of the camera" and be given "the opportunity, both prior to the initiation of the surveillance and periodically during it, to express its views of the surveillance and proposed changes in its execution, through a hearing or some other appropriate means." (Standard 2–9.3(b)(ii).) Use of detection devices at roadblocks is regulated in a similar fashion. (Standard 2–9.6(a)(iv).)

The requirement that a high-level law enforcement official or an accountable government body be involved in the decision to set up a public video surveillance and detection device at roadblocks is important for a number of reasons. First, these higher-level decision makers are more representative of the public than is a supervisor or field officer. In addition, a decision that is likely to affect large numbers of people for a long period of time should not be made by a low-level official, regardless of the latter’s expertise and knowledge of local conditions. Finally, only at the departmental level are the relevant statistics necessary for documenting a crime problem likely to be available.

Although the involvement of politically accountable officials allows for indirect public input, the Standards recommend that the public be given an opportunity to register its concerns more directly as well. Both from a philosophical and practical standpoint, government searches that affect large groups of people should be mediated through the political process. If the public is involved in approval of the surveillance it is more likely to understand its nature and purpose, any sense of discomfort associated with the surveillance is likely to be minimized, and the surveillance is more likely to meet the needs of the citizenry. Note, however, that the Standard limits public involvement to those "to be affected by the surveillance." This group would include those who live in or frequent the area to be surveilled, but generally would not include the public at large, which might be insensitive to the intrusion represented by mounted cameras in someone else’s neighborhood.

The import of these substantive justification requirements is to apply Fourth Amendment rules to technologically-assisted physical surveillance that infringes reasonable expectations of privacy and to recommend lesser, but meaningful limitation on other uses of such surveillance. The Standards also recommend various rules governing execution of surveillance. For instance, "the subjects of the surveillance should not be selected in an arbitrary or discriminatory manner," Standard 2–9.1(d)(i), "the scope of the surveillance should be limited to its authorized objectives and be terminated when those objectives are achieved," Standard 2–9.1(d)(ii), and "the particular surveillance technique should be capable of doing what it purports to do and be used solely for that purpose by officers trained in its use," Standard 2–9.1(d)(iv)).

Post-surveillance notice, disclosure, and record maintenance

Several other aspects of physical surveillance have yet to be addressed extensively by statute or Fourth Amendment case law. Three of the most important issues in this vein concern government’s obligations after the surveillance has been conducted. Under what circumstance, if any, must surveillance subjects be notified of the surveillance? To whom may surveillance records be disclosed? And how long, and under what conditions, may such records be maintained? Insufficient attention to these issues can result in privacy infringement of much greater magnitude than that associated with the initial surveillance.

Under both the Electronic Surveillance Standards and Title III, post-surveillance notice of communications surveillance must be given to all those listed on the warrant application. Notice in probable cause situations might even be constitutionally required in these situations. ( See Berger v. New York, 388 U.S. 41 (1967).) Some thought was given to expanding this notice requirement to all physical surveillance based on probable cause, not just surveillance based on a warrant. As in the communications surveillance context, the rationale for this approach is that the intrusion associated with physical surveillance that requires probable cause is significant, yet usually undiscovered by the target unless prosecution takes place. Indeed, when the surveillance does not require a warrant, a notice requirement is arguably even more important because no one other than the police will know about the surveillance unless prosecution occurs, in which case the effect of hindsight bias will often favor the police.

However, elaborate post-surveillance notice requirements would obviously burden law enforcement. Thus, the Standards require post-surveillance notice only when the surveillance is authorized by court order, and only to those listed in the order. At the same time, they provide that "notice to the principal target(s) of the surveillance may also be appropriate for other surveillance requiring probable cause." (Standard 2–9.1(d)(v)(B).) To avoid prematurely alerting a suspect or foiling an investigation, these notice requirements can be delayed for good cause.

Another reason for notifying targets of surveillance is to give them some chance of preventing further disclosure of the surveillance results. Some types of physical surveillance technology, particularly digital video surveillance and the tracking technology involved in intelligent transportation systems, make recording of activities and storage quite easy. To date, the law has devoted very little attention to the types of problems this recording and storage capability raise.

Consider two examples. First, suppose the government conducts surveillance of a business to determine whether drug importation laws are being violated. Assuming the surveillance is legally justified, the use of any information obtained is certainly permissible in a criminal prosecution on drug importation or related charges. However, the information might also be sought by other government agencies (e.g., an environmental protection unit), by competitors, or by private news organizations. Another example: a school’s video surveillance tapes of its halls are sought by police investigating criminal activity. Should disclosure be automatic in these situations? If not, what rules should govern the disclosure and retention of surveillance records?

Because these questions involve obtaining preexisting information, they are best answered by standards governing transactional surveillance, a subject that, as we noted earlier, will eventually be governed by a discrete set of standards. The Physical Surveillance Standards nonetheless also provide general recommendations about disclosure and retention issues, for two reasons. First, the propriety of a search or seizure depends in part upon what is done with the information obtained. Even if the police have probable cause to search a house, a decision to display all of its contents in the public square is unreasonable. Second, dissemination of information is itself an invasion of privacy. Such dissemination may be permissible if consistent with the purpose of a duly authorized search, but a violation of privacy rights may occur if the information obtained is used for other purposes.

For these reasons, the Standards provide that disclosure and use by law enforcement officials of information obtained through technologically-assisted physical surveillance "should be permitted only for designated lawful purposes." (Standard 2–9.1(d)(vi).) By limiting disclosures to "designated" lawful purposes, this Standard expresses a preference that such disclosures be prohibited unless affirmatively authorized by a statute, judicial decision, or agency rule. This requirement has at least three advantages compared to a decision by a lower level official: (1) legislative, judicial or agency action is more likely to be based on consideration of all the complex state and individual interests involved; (2) disclosures motivated by discriminatory or vindictive motives are less likely; and (3) review of any disclosure decision is facilitated.

The Standards also provide that "protocols should be developed for the maintenance and disposition of surveillance records not required to be maintained by law." (Standard 2–9.1(d)(vii).) A more bright-line approach would be to destroy such records unless the law directs otherwise. Destruction would either occur after the records are used for their intended law enforcement purpose, or when that purpose is no longer likely to be achieved. However, analogous to the approach taken in the Electronic Surveillance Standards, this Standard does not endorse that approach, because records can often have unanticipated benefits, not just in terms of incriminating the culpable, but also as a method for absolving the innocent. Such records might even be useful in demonstrating abuses by police agencies or in refuting false claims of such abuse. Instead, therefore, the Standard requires that agencies develop clear rules for maintaining (and destroying) records, limited, of course, by any laws that are passed.

A final related issue—particularly pertinent in the wake of September 11, the passage of the USA PATRIOT Act, and increased fears of terrorism—concerns the interaction of these disclosure and retention rules with the substantive limitations discussed earlier. One could argue that, if adequate protection against inappropriate disclosure to nonlaw enforcement entities exists, other restrictions on covert surveillance (e.g., suspicion requirements) could be minimized or eliminated. This position assumes that the surveillance itself, because undetected by the targets, does not harm any individual interests, and that disclosure of results, because limited to law enforcement purposes and other authorized objectives, does not harm innocent people. The second assumption, at least, is erroneous. Even if the surveillance results are used only against the guilty, the knowledge that the government is conducting covert surveillance without restraint would ultimately affect everyone’s sense of security. Further, if information is disclosed for purposes other than law enforcement, even if pursuant to a preexisting rule, the privacy of innocent people may be infringed. Thus, while proper precautions regarding disclosure can minimize the injury to privacy, they do not obviate the need for standards requiring justification for a particular surveillance.

Detection devices

Standard 2–9.2(b) defines a detection device as one that allows users to "detect the presence" of particular objects or characteristics through "opaque inanimate barriers" such as clothing and walls. This definition thus specifically excludes devices that can detect microscopic or transparent particles (e.g., cocaine, fluids, or fingerprints) that are invisible to the naked eye even when no barrier between the items and the eye exist. Use of the qualifier "inanimate" is meant to exempt from the purview of these Standards devices such as breathalyzers or X-rays that permit detection of the contents of one’s body. Government use of the latter devices is not easily labeled "surveillance" and, in any event, is already governed by a significant body of case law.

Several different types of detection devices exist or are on the verge of production. One example of the type of technique contemplated by this definition registers the degree of radiation emitted from the body and objects concealed on it. Because these waves readily pass through clothing, and because the body is a good "emitter" as opposed to metal and other dense, inanimate objects, the latter objects show up on the device as outlines against the body. Another example of a detection device is an instrument that aims a low intensity electromagnetic pulse at the subject and measures the time decay of each object radiated, a period that differs depending upon the object. The device then compares the time decay of the object with known "signatures" of items such as guns; no image or outline of the item is produced. A third example is a device that measures the fluctuations in the earth’s magnetic field produced by ferromagnetic material (like the metal in a gun) that moves through it. A fourth is the panoply of thermal imaging devices that measure the "heat waste" emitted from behind opaque barriers. This definition encompasses all of these devices, whether they are passive (as with the radiation and thermal imaging devices) or active (as with X-rays), and whether they produce an image of the object (as with the radiation device) or simply register the presence of an item or a characteristic.

Standard 2–9.2(b)’s definition of detection devices also recognizes that detection devices may detect only contraband (which are the Standards labeled "contraband-specific"), only weapons (labeled "weapon-specific"), or a variety of hidden objects in addition to contraband and weapons (what might be called a "general detection device"). Most devices are of the latter variety. For instance, an X-ray of a container may reveal not only a gun, but also the outline of other stored items. A magnetometer at an airport reveals not only the presence of a weapon but of keys, money, and other metallic objects. These devices would not be contraband- or weapon-specific, either because they identify noncontraband as well as contraband or because they do not clearly identify an object as either. On the other hand, a device that could mimic the behavior of some specially trained dogs by alerting only to the presence of drugs would be "contraband-specific." A device that detected only the presence of guns would be "weapon-specific."

The specific–nonspecific distinction is important in light of case law that suggests that the Fourth Amendment is not implicated by a police action that detects only contraband ( United States v. Place, 462 U.S. 696 (1983); United States v. Jacobsen, 466 U.S. 109 (1984).) Under Standard 2–9.2(b), whether something is "contraband" will depend upon whether the item is "virtually always criminal to possess or use in the existing circumstances." Carrying drugs like marijuana and cocaine is virtually always criminal. Concealing a weapon, on the other hand, may not be. Possessing a weapon is virtually always criminal if it occurs at an airport, and concealing a gun is usually criminal in states that limit who can do so to a small group of people (usually law enforcement officials and similar professionals). But in states where carrying a concealed weapon is legally permissible, a device that detected only guns would generally not be a contraband-specific device under this definition.

These distinctions are important to the Standards’ scheme governing use of detection devices. Under Standard 2–9.6(a), a general detection device may only be used to observe a private place in those situations in which a Fourth Amendment search may take place. Thus, a general detection device may be used to check out a home, car, or person only when there is a warrant, consent, a lawful arrest has occurred, lawful grounds exist for a car search or a frisk, or a roadblock has been set up to implement a compelling government interest in detecting weapons or contraband. Under Standard 2–9.6(b), on the other hand, contraband-specific devices may be used any time they are "reasonably likely to achieve a legitimate law enforcement objective," with two limitations: They may not be used to search a house or a person without the requisite Fourth Amendment suspicion, and, if their use requires a seizure of the person, there must be a legitimate basis for the seizure. Finally, under Standard 2–9.6(c), weapon-specific devices may be used, "even absent any individualized suspicion of danger that otherwise would be required," to "frisk" lawfully stopped individuals, survey an area prior to a legitimate no-knock entry, and carry out protective sweeps after a lawful arrest. These various provisions raise a number of controversial issues.

First, consider the recommendations governing general detection devices. It might be argued that use of such devices should always require probable cause (even if a recognized exception to probable cause exists) because they often reveal more than would a traditional, legitimate physical search. To illustrate, suppose the police have grounds to frisk a suspect or search the immediate premises surrounding an arrestee based on a reasonable suspicion of danger. A detection device that can "see" into containers might easily reveal more than a traditional search in these situations. The detection device Standard nonetheless incorporates all of the traditional exceptions to the probable cause requirement, for three reasons. First, the use of a detection device permits the officer to remain a safer distance from the suspect. Second, it avoids the need for highly intrusive placement of hands over the suspect’s entire body. Third, it identifies weapons and other items with greater certainty and locates them with greater precision. Thus, post-frisk searches into clothing will be fewer in number and more limited in scope. Similarly, in home entry situations, the use of detection devices might dissipate the fear of danger, so that "no-knock" entries will become unnecessary. In protective sweep situations, detection devices will give the officer a more definite reading concerning others on the premises and will decrease the chances of a dangerous surprise confrontation.

When the device used is contraband-specific, these arguments are even more powerful because only contraband is detected. Indeed, because the Court has strongly suggested that a search that reveals only contraband discovers nothing of "significance" ( Jacobsen v. United States, 466 U.S. 109, 118–19 (1984), one could contend that use of a contraband-specific device should not require any justification (assuming no seizure or any other physical interference is necessary). The Standards nonetheless provide that when surveillance is of the home or of the person the use of such a device should be permissible only upon probable cause. It was concluded that citizens should be entitled to these two places of ultimate repose, sacrosanct from suspicionless invasion regardless of the precision that technology affords. Some of those involved in drafting the Standards may also have been influenced by the reality that devices that can see through walls are unlikely to detect only contraband and that, even if they did, they could easily be used in a discriminatory fashion that would be particularly repugnant when aimed at the home or person.

Finally, the Standards’ position regarding weapon-specific devices requires further elaboration. In many situations (e.g., airports, jurisdictions where carrying a concealed weapon is a crime), a weapon-specific device will also be a contraband-specific device. However, in those jurisdictions and places in which carrying a concealed weapon is not a crime, use of such a device would be a search, because it would not be authorized by the Place-Jacobsen rationale. Nonetheless, the Standards permit use of a weapon-specific device whenever police have lawfully stopped an individual, lawfully entered premises without notice, or lawfully arrested an individual inside a home. This provision, in other words, eliminates any requirement that police have the articulable suspicion of danger typically required for a frisk ( Terry v. Ohio, 392 U.S. 1, 24 (1968), no-knock entries ( Richards v. Wisconsin, 520 U.S. 385, 394 (1997), or full-scale post-arrest protective sweeps ( Maryland v. Buie, 494 U.S. 325, 333 (1990)). When the search is narrowed to what a weapon-specific device would detect, the Standards reason, it should be permissible even when a reasonable officer would not have a suspicion that the person was armed and dangerous or that premises harbored a fugitive, for the only intrusion into privacy that the device poses is determination of whether, in fact, there was potential danger.

As a practical matter, this provision regarding use of weapon-specific devices does not add much to police power. Courts have long recognized that the requisite "armed and dangerous" probability for a frisk is lower than the probability of criminality needed for the stop itself. With the proliferation of weapons in recent years, courts have broadened even more the circumstances in which a protective frisk is appropriate to the point where it is almost coincident with the automatic "frisk" authority discussed here (David Harris, Frisking Every Suspect: The Withering of Terry, 28 U.C. Davis L. Rev. 1, 5 (1994).)


Innovations in the technology of law enforcement investigation have been dramatic and fast-paced. Law enforcement agencies, judges, and others who must evaluate the propriety of using communications and physical surveillance devices need more guidance than they now have, not simply in terms of specific rules but also with respect to the competing values to be weighed in making decisions about how and when to use these technologies in law enforcement. The ABA’s Criminal Justice Section Standards Committee, with the help of its task force, was able to draw on a wide body of knowledge and to assess the needs of law enforcement as well as the concerns of private citizens in devising the Electronic Surveillance Standards and the Standards on Technologically-Assisted Physical Surveillance. The end result are two sets of Standards that incorporate both general provisions and more detailed rules governing use of communication and physical surveillance techniques. The hope is that these Standards will encourage the development—by legislatures and administrative bodies, as well as by courts—of even more specific written rules governing technological surveillance, rules that take into account the technological revolution described in this article and that strike an appropriate balance between privacy and the legitimate needs of law enforcement.

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