Prosecutorial Misconduct

Prosecutorial misconduct is any courtroom behavior on the part of the prosecutor that violates trial rules and denies defendants their right to due process. Examples of misconduct may include making unfair or improper comments about the defendant, defense counsel, or a defense witness; suppressing, tampering with, or fabricating evidence; or making material misstatements regarding law or fact. The legal and psychological importance of examining prosecutorial misconduct is its potential to induce a jury to consider improper factors during the decision-making process.

Legal scholars contend that prosecutorial misconduct often occurs because of the prosecutor’s quest to secure a conviction. In doing so, prosecutors compromise impartiality by using improper methods to establish guilt—for example, inappropriately inferring guilt from a defendant’s silence. Although higher courts consistently express disapproval of improper prosecutor conduct, they frequently affirm the conviction, concluding that some prosecutorial errors are harmless. For an error to be considered harmless, reviewing courts need to establish that the outcome of the trial was not significantly affected by the error.

Forms of Prosecutorial Misconduct

The most common form of prosecutorial misconduct occurs in argument to the jury; however, it can also take place in evidence hearings, opening statements, and cross-examination. For example, it is misconduct to comment on a defendant’s failure to testify. Similarly, it is improper for the prosecutor to address the credibility of the testimony of codefendants or co-conspirators. Commenting on a defendant’s silence, or inferring questionable relationships among defendants, improperly suggests guilt and encourages a jury to find the defendant guilty. It is also considered misconduct for the prosecutor to question the integrity of the defense counsel. This includes unconfirmed claims that defense counsel fabricated evidence, courtroom displays of dissatisfaction with defense witnesses, or interruptions of defense objections. In general, any unsupported, damaging comments on the part of the prosecutor that challenge a defendant’s constitutional rights can be considered misconduct.

A review of appellate decisions also finds prosecutors cited for misconduct regarding issues related to evidence. Prosecutors must not introduce or attempt to introduce inadmissible evidence and, in the same vein, must disclose evidence favorable to the defendant. It is misconduct for prosecutors to use false or misleading evidence, misrepresent evidence to the jury, or destroy or tamper with evidence. In addition, it is improper for the prosecutor to make material misstatements of law or fact. Opening statements must be limited to offering admissible evidence, and closing arguments must be limited to evidence presented. Repeated instances of uncorrected misstatements could result in ordering a new trial.

Prosecutorial Misconduct in Capital Trials

Prosecutorial misconduct has been identified as a leading cause of unfairness during the sentencing phase of capital trials. Courts have expressly condemned this type of misconduct, which occurs in closing arguments. Defense attorneys contend that improper prosecutor remarks during the closing argument have the potential to inflame the sentencing jury if the argument introduces arbitrary factors to the jury’s recommendation of the death penalty. Empirical evidence indicates that individuals exposed to improper statements made by the prosecutor in the closing argument recommended the death penalty significantly more often than those not exposed to the statements. These results support the need to address regulating the penalty phase to minimize the likelihood that the jury will sentence the defendant to death for improper reasons.

Although the Supreme Court has not yet established specific guidelines determining the parameters of permissible prosecutorial argument, lower courts have provided general principles for defining improper penalty-phase arguments. In general, prosecutors are prohibited from stating their personal belief in the death penalty or from referring to their discretionary decision to seek the death penalty. It is misconduct to mislead the jury about its responsibility by implying that imposing the death penalty would deter others or protect the community. It is also considered improper to argue support for the death penalty in a religious context. Some state courts have ruled it improper for prosecutors to discuss the impact of the crime on the victim’s family or to argue that a victim’s family deserves a particular verdict. Overall, rulings on improper prosecutor arguments appear to be based on distinguishing between those that merely communicate misinformation and those that introduce extralegal factors that are likely to influence a jury’s sentencing recommendation.

Remedies for Prosecutorial Misconduct

There is a considerable body of legal literature addressing remedies, or cures, for prosecutorial misconduct. Legal professionals concur that prosecutorial misconduct is unlikely to affect the jury if countered by the defense attorney’s objections or corrected by the judge’s instructions. The Supreme Court has indicated that arguments with the potential to unduly influence the jury should be clarified by a specific judicial instruction. This instruction rebuts the inferences or implications made by the prosecutor in the closing argument. Similarly, defense attorneys stress the need to form prompt, articulate objections to improper statements to avoid any problems on appeal. The underlying assumption of each of these legal safeguards is their potential to minimize the effects of the prosecutor’s improper argument on the jury.

In assessing the effect of prosecutorial misconduct, the pertinent question is whether the misconduct caused the trial proceedings to be fundamentally unfair. The standard for reviewing a prosecutor’s improper penalty-phase argument is whether the argument affected the defendant’s due process right or whether the argument unduly influenced the jury’s recommendation of death.


  1. Berger v. United States, 295 U.S. 78 (1934).
  2. Brooks v. Kemp, 762 F.2d. 1383 (11th Cir. 1985).
  3. Chapman v. California, 386 U.S. 18 (1967).
  4. Darden v. Wainwright, 477 U.S. 168 (1986).
  5. Gaskill, J. B. (1991). Prosecution misconduct in trial: The improper attempt to influence the jury. California Attorneys for Criminal Justice Forum, 18(5), 12-25.
  6. Platania, J., & Moran, G. (1999). Due process and the death penalty: The role of prosecutorial misconduct in closing argument in capital trials. Law and Human Behavior, 23, 471-186.

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