Prosecutorial Misconduct and Mistrials

When does prosecutorial misconduct cause a mistrial? When it does, is retrial possible? Or is retrial barred, resulting in the dismissal of the charges? If retrial is barred, the mistrial is said to be “with prejudice.” In this column, we analyze the legal and ethical aspects of prosecutorial misconduct that results in a mistrial. We also examine the reasoning and factors courts use in deciding whether to allow a retrial after such misconduct.

Mistrials

A mistrial essentially stops a trial and declares it invalid, usually before a verdict. The most common reason is a jury being unable to reach a verdict, often referred to as a hung jury. There are other reasons for mistrial that, like the hung jury, are not the fault of the prosecution, defense, or judge. These include a juror discussing the case with nonjurors during trial or the illness or death of the prosecutor, judge, or defense counsel. When a mistrial occurs for any of these reasons, retrial is not barred. Such mistrials are said to have been granted due to “manifest necessity.” United States v. Perez, 22 U.S. 579 (1824).

Misconduct by the prosecutor is another reason a mistrial may be declared. When prosecutorial misconduct causes a mistrial, as discussed below, retrial may or may not be allowed.

A Remedy for Misconduct

Under limited circumstances, retrial after a mistrial caused by prosecutorial misconduct will be barred. In essence, barring retrial serves as a remedy for the prosecutorial misconduct that caused the mistrial.

The double jeopardy clause of the Fifth Amendment of the U.S. Constitution prohibits repeated prosecution of a defendant for the same offense. When the double jeopardy clause is triggered, it is said that “jeopardy attaches.” Jeopardy attaches when the jury is sworn in or, in a bench trial, when the prosecutor introduces the first evidence. Once this has happened, with few exceptions, a retrial is barred.

When a mistrial is granted at the request or with the consent of the defendant, a trial court usually considers any double jeopardy barrier to retrial waived. A limited exception is when the defendant’s motion for a mistrial is based on prosecutorial misconduct, such as the misconduct prompting the Rittenhouse motion. Fifty years ago, the Supreme Court acknowledged that “bad faith” conduct by a prosecutor could preclude a retrial due to double jeopardy. United States v. Jorn, 400 U.S. 470, 485 (1971). But what constitutes “bad faith”? What misconduct is sufficient to bar retrial?

Purpose to Cause a Mistrial

Oregon v. Kennedy, 456 U.S. 667 (1982), establishes the controlling federal constitutional law on barring retrial as a remedy for prosecutorial misconduct causing a mistrial. In Kennedy, the U.S. Supreme Court focused on the prosecutor’s mental state and held that purpose to cause a mistrial bars retrial. Kennedy vests a great deal of responsibility and discretion in the trial judge, who must decide whether the prosecutor purposely provoked a defense motion for a mistrial.

Requiring a defendant to prove a prosecutor’s purpose to cause a mistrial in our view is unduly burdensome. Few defendants have succeeded in doing so since Kennedy was decided. Federal and state courts adopting the Kennedy standard have permitted retrials after mistrials due to prosecutorial misconduct that included improper questions during direct or cross-examination, disobeying court orders, improper comments about defense counsel, and improper remarks in opening statement or closing argument.

Given the practical difficulty of proving prosecutorial purpose, a defense decision to move for a mistrial in response to prosecutorial misconduct is fraught with uncertainty and strategic risks. If the judge grants the motion for a mistrial but permits a retrial, the defendant loses any opportunity for the first jury to acquit. Additionally, the accused faces the expense, delay, and emotional costs of a second trial. Retrial provides the prosecutor with the possible strategic advantage of shaping a response to strengths and weaknesses seen at the first trial in both the prosecution and defense cases. On the other hand, a mistrial ensures that the jury at the first trial will not be swayed by prosecutorial misconduct in deciding the fate of the accused and the judge may grant the mistrial with prejudice.

A prosecutor who engages in misconduct to cause a mistrial violates ABA Model Rule 8.4(d), which prohibits “conduct that is prejudicial to the administration of justice.” Cases from several jurisdictions have held that violation of Model Rule 8.4(d) requires improper conduct that affects the judicial process. See, e.g., In re Carter, 11 A.3d 1219, 1224 (D.C. 2011) (stating that to violate Rule 8.4(d), the conduct must be “improper, bear directly upon the judicial process,” and “taint the judicial process in more than a de minimis way”). Model Rule 8.4(d) has no mental state requirement. It just requires the lawyer’s conduct to prejudice the administration of justice. See, e.g., In re Alexander, 300 P.3d 536, 546 (Ariz. 2013) (stating that Rule 8.4(d) has no mental state requirement and the lawyer’s motives are “immaterial”).

Model Rule 4.4(a) prohibits conduct that has “no substantial purpose other than to embarrass, delay, or burden a third person . . .” (emphasis added). A prosecutor who engages in misconduct to cause a mistrial delays resolution of the case, burdens the defendant with the time and expense required if there is a retrial, and denies the defendant a fair first trial.

Prosecutors have rarely been publicly disciplined for violating Rule 8.4(d) or 4.4(a), and we could find no public discipline cases for prosecutors whose misconduct prompted mistrials. This lack of public discipline is likely a reflection of the unfortunate reality that prosecutors in general are rarely disciplined.

No Purpose to Cause a Mistrial

The decision in Kennedy was based on the Double Jeopardy Clause in the U.S. Constitution. Some state courts have adopted more expansive and less burdensome interpretations of the double jeopardy clauses in their state constitutions. After the Kennedy case was remanded, Kennedy appealed to the Oregon Supreme Court under the Oregon Constitution. The court held that Oregon’s Double Jeopardy Clause bars retrial “when improper official conduct is so prejudicial to the defendant that it cannot be cured by means short of a mistrial, and if the official knows that the conduct is improper and prejudicial and either intends or is indifferent to the resulting mistrial or reversal.” State v. Kennedy, 666 P.2d 1316, 1326 (Or. 1983). This standard does not require a defendant to prove the prosecutor acted with purpose to cause a mistrial. The court, however, left unclear precisely what mental state or states are encompassed by the word “indifference.” It did state that a prosecutor’s negligence or even gross negligence is not sufficient to bar a retrial, id. at 1324, suggesting that knowledge and recklessness, in addition to purpose, are sufficient.

The Arizona Supreme Court, in Pool v. Superior Court, 677 P.2d 261, 271–72 (Ariz. 1994), also held that the Arizona Constitution’s Double Jeopardy Clause diverges from the federal Double Jeopardy Clause. Under Pool, retrial is barred if the prosecutor engages in “conduct which the prosecutor knows to be improper and prejudicial, and which he pursues for any improper purpose with indifference to a significant resulting danger of mistrial or reversal.” The Arizona Supreme Court, like the Oregon Supreme Court, failed to define what “indifference” means.

State courts that do not require proof of prosecutorial purpose to cause a mistrial weigh a number of factors in deciding whether to bar a retrial. These include the seriousness of the misconduct, whether the misconduct is isolated or part of a pattern, and the prejudicial impact on the defendant. The timing of the misconduct and the strength of the state’s case are also factors. If the misconduct occurs toward the beginning of the trial, when it is too early for the prosecutor to determine that the case for conviction is weak, courts usually permit a retrial. If the misconduct occurs toward the end of the trial, as in summation, courts often find more prejudice to the defendant and greater likelihood that the prosecutor knew the conduct was improper and prejudicial and acted with at least indifference to the risk of causing a mistrial.

Conclusion

The law on whether and when prosecutorial misconduct that causes a mistrial bars a retrial suffers from a number of problems. Federal law, while clear in articulating its purpose requirement, is unduly burdensome on defendants. State law, in states such as Oregon and Arizona, is less burdensome on defendants but ambiguous on prosecutorial mental states other than purpose. A more fundamental problem with both federal and state law is that it focuses too much on proof of the prosecutor’s mental state. These mental states, which appear to be uniformly subjective and internal, present factual issues that will routinely be difficult for defendants to prove and for courts to resolve. One need look no further than the notorious practical proof problems that plague the constitutional law on discriminatory peremptory jury challenges to understand the problems that arise when defendants must prove and courts resolve factual questions about a prosecutor’s purpose.

A better and more workable approach is to focus on the egregiousness of a prosecutor’s conduct and/or the harmful result that conduct caused or risked rather than the prosecutor’s mental state. If the prosecutor’s mental state is retained as an element of a retrial standard, it is preferable to place the burden of proof on the prosecution to demonstrate that the misconduct was not accompanied by purpose or another improper mental state.

By focusing on the prosecutor’s mental state and placing the burden of proof on the defendant, current law may tempt a prosecutor whose case appears weak to engage in misconduct knowing that a retrial is likely to be allowed and that professional discipline is unlikely. Given these practical realities, the criminal justice system currently relies to an unhealthy degree upon prosecutors to act in conformity with legal and ethical rules prosecutors are likely to know are rarely enforced.