Edward Imwinkelried is a longtime evidence teacher and scholar at the University of California Davis School of Law. He has been cited in over 900 federal and state decisions—most notably in Daubert v. Merrell Dow Pharmaceuticals—and was listed as the evidence scholar most cited in other legal publications in a 2007 survey. His treatise Scientific Evidence, now in its fifth edition, is a classic in the field, and he has written more than 200 other books and articles.
MJS: Where did you grow up, and what aspects of your childhood stand out as most memorable?
EJI: There is nothing really noteworthy about my early childhood. I grew up south of Market in San Francisco in a blue-collar family. My dad was a fireman, and my mother was part-owner of a neighborhood grocery store. I attended a small Catholic grammar school, St. Patrick’s. They later razed the school buildings and replaced the school with a low-income housing project.
MJS: What pointed you toward law school?
EJI: I didn’t give any thought to being a lawyer before high school. No one in my family had ever gone to college. No one in the family was a lawyer. We moved to a more middle-class area in the outer Mission District when I began high school.
Because I was very shy, my parents insisted that I join the speech club at high school. That was certainly a turning point for me. At first, I hated it because I was a pretty quiet kid. However, early on I had some limited success. As the years passed, I won three district championships as well as two state championships. When the dust settled at the national finals at Rice University at the end of my senior year, I was the “high point” student at the tournament and the overall individual national champion.
As I had more and more success in speech, more and more people told me I should become an attorney. It was an impetus for a bunch of my high school classmates. I had four really close friends on the speech team. One became the leading bankruptcy specialist in San Francisco, another was the top aide in a large public defender office in the Bay Area, still another currently sits on the California Court of Appeal, and my debate partner recently retired as chief justice of the Alaska Supreme Court. We try to get together every so often.
MJS: You went to the University of San Francisco in the late 1960s—that had to be interesting.
EJI: It was not only interesting going to USF at that time—it was interesting getting to USF, since I had to drive right through the Haight-Ashbury district on the way there every day. I never really thought of leaving San Francisco to attend college. I lived at home and commuted. In addition, I liked USF because, as far as I could tell, it was the only California school offering a three-three program: go to undergraduate school for three years, then start law school, receive your BA at the end of the first year in law school, and attain your JD two years later.
MJS: Did any aspect of Haight-Ashbury rub off on you?
EJI: Of course, the music. In fact, my dad’s godfather was the grandfather of two of the members of Creedence Clearwater. At the time, I loved the Rolling Stones, especially the early albums inspired by R&B. I’ve since moved on to country and western. C&W has the sense of humor that rock and roll used to have.
MJS: Then you went to USF law school and graduated in two years; were you in a hurry to leave school?
EJI: I suppose that I was in a something of a rush. My parents sacrificed a lot to help me through school, and the least I could do was shave one year off the process. The accelerated pace didn’t worry me, since I had skipped a grade in grammar school and lived to tell about it.
MJS: Was it love at first sight when you encountered evidence in law school, or was it a romance that blossomed later?
EJI: It’s an understatement to say that my passion for evidence developed after law school. Evidence was one of my most frustrating law school courses. The professor had never taught the course before. He used to bring his hornbook (the first, 1954, edition of McCormick) with him to class to search through if he didn’t know the answer to a question. However, you had to give him high marks for honesty—on more than one occasion, when you came to class the next day, he’d distribute an errata sheet explaining why what he had said the day before was wrong. In retrospect, though, it’s a funny memory. I can still visualize that copy of McCormick on the professor’s desk. I’m now one of the authors of the seventh edition of the McCormick treatise.
MJS: I see you were first in your class in college, first in your class at law school, and first in your class at Judge Advocate General’s School. I’m noticing a trend there.
EJI: I think that in part because I finished at the top of the class, on graduation day, one of the professors took me aside and told me that I should think about teaching. His remark took me aback. I’d never even considered that possibility. Coming from a blue-collar family, I simply thought about practicing law to make a decent living and perhaps help some people along the way.
MJS: Then you served in the JAG Corps—tell us about that.
EJI: Before I graduated from law school, I realized it was probable that I would be drafted. In fact, I went through a pre-induction physical. I decided that rather than spending two years as an enlisted person and not using my legal training, I’d volunteer for the Army JAG Corps. It was a four-year obligation.
I did fairly well in the Basic Class at the JAG School at the University of Virginia. At the end of the Basic Class, they offered me a teaching position. However, just as I had laughed on graduation day when the professor suggested that I become a professor, I summarily rejected the offer. Naïve as I was, I wanted to get some “real world” experience.
My first post was as Post Judge Advocate for Rocky Mountain Arsenal in Denver, where a lot of the chemical munitions left over from World War II were stored. It was like being a solo practitioner. I did virtually everything—government contracts, claims, environmental law, helping enlisted personnel with taxes, and a bit of criminal justice. I sometimes helped out as defense counsel at nearby Fitzsimons Army Hospital.
MJS: You were in Vietnam, right? What was it like as a JAG officer there? What kinds of cases came up? Were you in or near combat?
EJI: After about a year in Denver, I received orders for Vietnam. I was initially assigned to XXIV Corps, an artillery organization. Corps headquarters, Camp Horn, was located in Danang, and our general was responsible for the northern quarter of the country. Our subordinate commands included some Marine units and the 101st Airborne. There was the occasional rocket attack—as I recall, the New York Times sometimes referred to Danang as “Rocket City”—but I was rarely in any real danger.
Our commander, General Dolvin, was a bright, open-minded manager, and my boss, the Staff Judge Advocate, Colonel Katayama, is the best person I’ve ever worked for. I don’t want to be disrespectful to any of the deans I’ve had, but Robert Katayama was an exceptional human being. When he retired from the Army, he returned to Hawaii and became a leader in the Hawaiian bar. To begin with, he was a fantastic attorney—probably the Army’s leading authority on government contract law. He was a complete gentleman and, at least in my presence, never swore in a profanity-laced environment. He treated everyone decently; it didn’t matter whether he was dealing with General Dolvin or Ba Luu, the elderly Vietnamese lady who cleaned my office. He treated everybody in the same friendly, polite fashion. And he was always honest with us. It was an honor to work for him.
My assignment didn’t include much trial work. On very rare occasions, I served as a summary court-martial officer—a judge with very limited punishment powers. Most of my work, though, related to claims. I arrived just as the claims officer was rotating back to the United States, and I consequently became Forensic Claims Commissioner 413. When the colonel took me to my new office, it looked like a Bekins warehouse. The office was full of boxes.
The colonel proceeded to explain that in the late 1960s a fire had spread to the Danang ammo dump, causing tons upon tons of ammunition to explode. Thankfully, there had been no loss of life. However, 4,500 Vietnamese homes had been destroyed. The boxes were full of the approved claims forms.
The colonel next took me to the Military Police station on the compound. He pointed to the detention cell behind the desk at the entrance. The cell was full from floor to ceiling with footlockers. The colonel said that all the footlockers were full of the money to be used to pay the claims. The colonel then handed me the only key to the cell. In the ensuing months, I learned lots about Army claim procedures.
MJS: We read a lot about decisions made by military and intelligence lawyers in the years after 9/11. Do you feel like you have special perspective on that having served in wartime, especially since some of the issues relate to evidence—that is, what evidence can be used in proceedings involving detainees?
EJI: Although my roommate and I lived across from two CIA operatives, we learned next to nothing about their operations or interrogation techniques. You know the old saw: “If we told you, we’d have to. . . .”
MJS: You said a couple people urged you to consider teaching. What clinched it for you?
EJI: Near the end of my tour in Vietnam, I received orders reassigning me to the JAG School. I was surprised because I hadn’t requested that assignment. At that point, I was mildly interested in teaching, and I had loved what I had seen of the University of Virginia campus in Charlottesville. However, the personnel people had led me to believe that I’d have to extend for a fifth year to be eligible for a teaching assignment. I was unwilling to give the Army another year, and I hoped that I would end up somewhere on the East Coast to do government contract work.
As I said, I thought that Colonel Katayama was a superb attorney, and I knew that was his specialty. Consequently, I was shocked when I received orders for the JAG School, especially since they wanted me to teach criminal law rather than claims! It turned out that Colonel Overholt, the head of the Criminal Law Division who had previously offered me the teaching position, had put in a request to bring me back to Charlottesville to teach for his division.
I soon discovered that I loved teaching. The then dean of the University of San Diego School of Law, Don Weckstein, was an Army reservist who spent his active duty time at the JAG School. I made his acquaintance, and that friendship was instrumental in getting me a teaching position at USD in 1974.
MJS: You’ve taught for over 40 years. Do you see any changes in the nature or qualities of law students now compared to when you began in 1972?
EJI: I’ve been teaching in one capacity or another for 44 years. I have noticed some changes in the law student population. To begin with, my impression is that, today, law students are more public-interested. I have to add two caveats, though. First, when I went to law school, many, if not most, of my classmates were from blue-collar families, and we tended to view becoming a lawyer primarily as a way of making a better living. At that time, there certainly weren’t many organizations to facilitate pro bono work by law students. That may skew my perception of my own generation of law students.
Second, for the past 30 years, I’ve been privileged to teach at the University of California, Davis, which has one of the most idealistic, public-spirited student bodies. That may distort my perception of the current generation of law students.
Another change is that this generation of law students is more earnest. When I began teaching, you’d encounter a fair number of jokes in the bluebooks. Now, students never joke in the bluebook. I fear that the tight job market makes many students extremely nervous about their future. I have fond memories of my three years in law school, and I’m afraid that some recent law graduates have had a qualitatively different—less enjoyable—experience. I hate to see a student walking down the hallway with a grim expression on his or her face.
MJS: What aspect of the Rules of Evidence or the case law proves consistently hardest for law students to grasp? For me, I’m sure it was hearsay.
EJI: The key for evidence is to appreciate the importance of creative logical relevance analysis—keeping your mind churning to find a second or third theory of logical relevance for an item of evidence. The most difficult part of hearsay analysis is determining whether the out-of-court assertion has to be offered to prove the truth of the assertion. Is there an alternative, non-hearsay theory of logical relevance?
Likewise, the key to mastering character is identifying a non-character theory of logical relevance. Rule 404(b) generates more published opinions than any other provision of the Federal Rules of Evidence. The inclusionary conception of the doctrine codified in 404(b) rewards the litigator who is imaginative enough to articulate a non-character theory.
The same holds true for rules of limited admissibility such as subsequent repairs and compromise statements. The rules preclude certain uses of the evidence, but if you can find an alternative theory, you can introduce the evidence.
And it’s not just that the creative use of logical relevance is crucial to defeating objections based on hearsay, character, and the limited admissibility rules. Even more importantly, that’s the aspect of evidence law that makes it satisfying to be a litigator. I vaguely recall that in one of the Socratic dialogues, a character laments that he has “only eyes enough to see what others show him.” I’ve always striven to help students become the lawyer who can see things—specifically, theories of logical relevance—that others are blind to.
MJS: Do you have any tips for litigators as to how to go about trying to identify those second or third theories of relevance?
EJI: The first theory that occurs to you will connect the item of evidence to one of the facts of consequence in the case under Federal Rule 401. However, depending on the crimes, causes of action, and defenses in play, there may be several other facts of consequence within the range of dispute. Don’t turn your mind off after finding the initial theory of logical relevance. See if you can imaginatively link the item to a second fact or a third fact.
MJS: One of the areas you’re closely identified with now is scientific evidence. What drew you to that?
EJI: Every week, the Criminal Law Division at the JAG School had a meeting. At one of the first meetings I attended, someone remarked that scientific evidence was popping up in a growing number of cases. Colonel Overholt decided that “someone” should go to the library and learn enough about the subject to teach a block of instruction. Of course, that “someone” was the newest addition to the division—namely, me.
Then, a few months later, Paul Giannelli arrived and became my officemate. Paul was fresh from earning his LLM in forensic science at George Washington. Paul’s arrival solidified my interest in the subject. Paul and I have been collaborators and, more importantly, great friends for over 40 years.
MJS: Daubert v. Merrell Dow Pharmaceuticals is probably the evidence-related decision best known to civil litigators. Every law student learns it, and every litigator eventually argues it. The Court cited not just one of your writings in Daubert, but two—one being your well-known treatise, Scientific Evidence. Were you involved in the case in any way, or just cited by the Court?
EJI: I worked as a consultant to the plaintiffs in Daubert. One of the primary authors of the brief was Ken Chesebro. Ken had read some of the articles I had written about Rule 402 and the 402-based contention that the Federal Rules of Evidence superseded Frye. Ken asked me to help him write the first part of the brief in which we developed that contention.
Working on the brief was a learning experience. The day before we were sending the brief to the printer, in the hour between 4:00 and 5:00 p.m., I received several faxes from Cambridge and sent several to Cambridge. As the clock was ticking to five and I had to be out the door to pick up my son from practice, I was dictating to the secretary in Cambridge as the last fax was coming off the machine. When I went home, I told my wife Cindy, “Now I remember why I don’t want to be a real, practicing attorney.”
MJS: Do you think the decision has worked out well in practice all these years later? Are there ways it’s applied that you think are off-base?
EJI: Daubert has had three incredibly important effects. First, it has forced attorneys and judges to ask the right questions. You don’t determine scientific merit by a show of hands at a scientific meeting. Rather, you critically assess the empirical data supporting the theory or technique. Once you have that insight, you can ask the meaningful questions about the size of the database, its composition, the test conditions, and the findings. Does the data show that by using that specific theory or technique, the expert can accurately draw the particular inference he or she contemplates testifying to?
Second, the case has forced the forensic science community to begin conducting the empirical studies that, in some cases, should have been conducted decades ago. However, given Frye, you can understand why, previously, government law enforcement agencies weren’t providing research funds to improve microscopic hair analysis or forensic odontology. The agencies have only so much funding, and if they can be confident the courts will continue to admit prosecution forensic testimony because it’s generally accepted, they have little incentive to make the investments needed to improve the state of the forensic art.
Third, at the most fundamental level, when Daubert announced that “arguably, there are no certainties in science,” the Court embraced a new, more realistic conception of the scientific enterprise. In investigational science, you largely rely on inductive reasoning. You formulate a hypothesis, you engage in empirical testing to validate or falsify it, and you assess the results of the test. No matter how many prior outcomes seem to validate the hypothesis, you can always conceive of another test; and so long as you can, in principle, you can never regard a hypothesis as conclusively proven to a certainty. The bottom line is that the courts should neither require nor permit expert opinions couched as certainties. Daubert ushered in a new era of intellectual honesty about scientific testimony in the courtroom.
Attorneys and judges can go “off base” if they expect too much. Remember that if you take Daubert seriously, a judge should neither require nor permit an expert to testify to an absolute certainty. When the judge makes an admissibility ruling under Rule 702, the judge is passing on the adequacy of the empirical support for the opinion, not the correctness of the opinion, and the issue is whether there is enough foundational support—not the best possible support. We’re condemned to an existential condition in which we’re always making decisions in conditions of uncertainty, in part caused by incomplete information.
MJS: But what about the criticism that judges are now required to perform quasi-scientific inquiries for which they’re not terribly qualified, even when they’re only supposed to be acting as gatekeepers? Another article in this issue quotes a Seventh Circuit judge who wrote, in essence, that many of us went to law school precisely because we weren’t interested in science. Obviously, a decision to shut the gate on certain expert evidence can effectively decide the case one way or the other.
EJI: As I said, I served as a summary court-martial officer in Vietnam—a sort of trial judge with limited punitive powers. Although I presided at only a small number of cases, I quickly discovered that, in many cases, the trial judge’s best friend is the allocation of the burden of proof. There’s a burden of proof under Rule 702. More specifically, it’s the proponent’s burden to convince the judge by a preponderance of the evidence under Rule 104(a) that by using this specific theory or technique, the proponent’s expert can accurately draw the particular inference that he or she proposes testifying to. The judge is not tasked to decide whether to award the expert a Nobel prize. The judge’s “gatekeeping” responsibility is to carefully review the foundational testimony presented by the proponent and decide whether the proponent has satisfied that burden. If the proponent hasn’t, you exclude the evidence. A judge with a good critical mind is competent to make that decision. The judge doesn’t need a PhD in nuclear physics.
MJS: I’m inferring from one of your recent articles entitled “Cell Tower Junk Science” that Daubert hasn’t always succeeded in keeping out dubious expert testimony. What is “cell tower junk science,” and did you listen to the Serial podcast deconstructing the Adnan Syed case?
EJI: I confess that I didn’t follow the podcast. I became a coauthor on a number of articles about cell tower evidence because I was contacted by Mike Cherry—first about fingerprint evidence and then about cell tower testimony.
MJS: How is it junk science, and how often is it being used these days?
EJI: It can be junk in the sense that the methodology employed by the expert doesn’t support the inference that the expert proposes drawing about the location of the caller. In the early cases, some courts allowed experts to opine that the accused was at a very specific location. The point is that on the facts in many cases, the only methodologies that are usable are techniques that allow the expert to infer only that the accused was in a very large geographic coverage area. Again, it’s the problem of the overstated inference. Fortunately, thanks in part to people like Mike Cherry, many courts no longer admit such overstated conclusions.
MJS: Fingerprint evidence has also recently come in for criticism, including in this journal. Do you think it’s reliable?
EJI: No one seriously doubts that if an examiner can compare 10 clear prints against 10 clear prints, as in the immigration context, you can make a reliable identification. However, in the forensic world, the examiner is typically working with a single, partial, distorted impression.
To be sure, there are some technical problems. If the electronic file containing the image is too compressed, you can lose detail that would exculpate a suspect. If you digitally enhance the image, the manipulation can also destroy vital details.
However, the larger problems are the ones mentioned in my answer about how Daubert has played out in practice. In the past, examiners sometimes asserted that they could exclude every other person on the face of the earth—or, even more extremely, every person who has ever walked on the face of the earth. Examiners made unjustifiable claims to certainty. In addition, until Daubert, the fingerprint community failed to conduct some of the empirical research needed to develop a more defensible, probabilistic model. Researchers such as Sargur Srihari at SUNY Buffalo are now pioneering the research.
MJS: What about eyewitness evidence—has there been much progress in excluding eyewitness evidence when law enforcement uses old, dubious lineup or photo procedures?
EJI: The psychological research has come a long way, although most courts still lag behind the research. However, the real point is that an awareness of the limitations of eyewitness testimony should give all the more motivation to improve the forensic identification disciplines. Strong forensic evidence is the best antidote for weak eyewitness testimony.
MJS: Why do you think courts lag behind? There’s certainly no shortage of lawyers making the necessary arguments and bringing the evidentiary shortcomings to their attention?
EJI: Many judges had years of experience with the Frye general acceptance before their jurisdiction shifted to Daubert’s empirical validation test. It’s a major adjustment to stop asking how popular the methodology is and to begin demanding the specifics about the size of the study, its composition, etc. Although the courts certainly don’t get it right all the time now, we’ve made considerable progress. Once a judge knows the right questions to ask and develops a comfort level working with empirical data, he or she will become a competent gatekeeper. As one of my colleagues sometimes remarks, “Even a glacier moves.” And the glacier will move even faster when the judiciary is staffed primarily with judges who learned Daubert in law school and used that standard in practice before their judicial appointment.
MJS: Is there any other kind of routinely admitted scientific evidence that courts ought to be taking a harder look at?
EJI: Fortunately, we’re making real progress reevaluating arson evidence. You might take a look at Mark Hansen, Badly Burned: Long-Held Beliefs about Arson Science Have Been Debunked after Decades of Misuse and Scores of Wrongful Convictions, 101 A.B.A. J. 37 (Dec. 2015). I have a special interest in that topic because, as I mentioned, my late dad was a fireman. When we published the very first edition of Scientific Evidence, my dad was kind enough to review the arson chapter for us.
MJS: Have you testified in criminal cases?
EJI: No. I have a BA in political science with minors in philosophy and English literature. No judge in his or her right mind would consider me an expert on a scientific evidence issue. I’ve been asked to testify in the past, but I’ve always said no. I have a modicum of common sense.
MJS: In a recent article, you argue that discovery reforms sometimes have unintended consequences that affect the treatment of evidence at trial, and that evidence reforms can affect discovery practice. So you advocate a systemic approach to improving both. What are some examples of these unintended consequences, and what would systemic reform look like?
EJI: The perfect example is the relationship between discovery and privilege law. Until recently, the scope of discovery was incredibly broad. In one case, the judge ordered the discovery of 10 terabytes of information—more pages than are evidently contained in the entire Library of Congress collection. At the same time, some courts adopted a strict standard for privilege waiver and treated even inadvertent disclosures as waivers.
The result was that producing parties had to spend small (or relatively large) fortunes on pre-production privilege reviews. The cost of such a review could pressure a litigant into settling even though they were right on the merits of the case. Fifty years ago, roughly 11 percent of the cases filed in federal court culminated in a trial. Today that figure has fallen to about 1 percent. Today pretrial discovery is the center of gravity in litigation. This is probably a declaration against interest for an evidence teacher, but we shouldn’t let the tail (the trial evidence rules) wag the dog (pretrial discovery).
MJS: How do you think the recent revisions to the discovery rules will affect evidence law?
EJI: At the very least, the amendments should enable the court to get to the point of pretrial privilege disputes earlier in the process. To begin with, the Rule 34 amendments prohibit boilerplate objections. Moreover, they provide that when the producing party objects, the producing party must indicate whether any responsive material is being withheld on the basis of an objection. In the past, the producing party’s response was occasionally so vague that the party seeking discovery couldn’t even determine whether the producing party was implicitly asserting a privilege and, on that basis, withholding material.
MJS: Discovery rules and practice have obviously struggled to adapt to the proliferation of all kinds of electronic evidence. Has that been true of evidence law as well?
EJI: History keeps repeating itself. When motion pictures made their advent, some courts were so concerned about manipulation and fraud that they announced onerous admissibility requirements. The same thing happened when video technology became available.
We’re seeing the same phenomenon with respect to electronic evidence and social media postings. In each case, common sense eventually prevailed, and most courts came to appreciate that, though they were dealing with a novel technology, the same basic principles, including the conditional relevance standard codified in Rules 104(b) and 901(a), should govern.
Don’t be intimidated by the new technical terminology. Turn to the proponent and insist that the proponent explain in clear, understandable terms why the foundation is powerful enough to show that the item of evidence is what you claim it is. The conditional relevance principle is flexible enough to adapt to evolving technology.
MJS: What cutting-edge issue in evidence that’s under the radar now is most likely to surface and preoccupy litigators in the next few years?
EJI: I think that there are two things worth keeping an eye on. First, microbial analysis is coming. Even if a perpetrator is astute enough to avoid leaving DNA at a scene, it’s almost impossible to avoid leaving part of your microbial community. Microbial analysis may also help improve time-of-death estimates.
Second, attorneys and judges will come to learn about forensic metrology. Metrology is the science of measurement. The basic tenet of metrology is that you can never be certain that a measurement captures the true value of the measurant—harking back to Daubert’s acknowledgment of the uncertainty of the scientific enterprise. Metrologists argue that whenever you cite a measurement, you should provide an arithmetic measure of the associated uncertainty, often a confidence interval. If you provide the decision maker with both the statistic (the sample mean) and a confidence interval for the mean, the decision maker has a much better sense of the reliability of the statistic. The 2009 report from the National Research Council of the National Academies of Sciences recommended that laboratories provide accompanying uncertainty measures with their statistics. A physicist/attorney named Ted Vosk is raising the legal community’s consciousness of this issue. In 2015, Ted and Ashley Emery released Forensic Metrology: Scientific Measurement and Inference for Lawyers, Judges, and Criminalists (CRC Press). The need for an arithmetic measure of uncertainty has already become a hot-button issue in intoxication testing.