“Stricken from the record”: curative instructions, mistrials, and the legal fiction of jury disregard

Objection! Motion to Strike! These words are used frequently in U.S. courtrooms. When improper evidence is introduced in a criminal trial, judges often instruct jurors to “disregard” the testimony or strike it from the record. Courts operate on the presumption that jurors follow such instructions, even though jurors have already heard the information. This creates a tension between human cognition and legal foundation raising an important question in criminal adjudication. When is striking evidence sufficient to cure prejudice, and when is the prejudice so severe that a mistrial or new trial is required?

Trial judges possess broad authority to exclude or strike evidence that is unfairly prejudicial or otherwise inadmissible under the Federal Rules of Evidence, including Federal Rule of Evidence 403, which permits exclusion when probative value is substantially outweighed by unfair prejudice or confusion. Courts also rely on Federal Rule of Evidence 103, which governs rulings on evidence and preservation of evidentiary errors for appeal. When inadmissible evidence is presented, the most common remedy is a curative instruction, in which the judge directs the jury to disregard the testimony or exhibit. Courts presume jurors follow such instructions, a principle repeatedly reaffirmed by the Supreme Court as essential to the functioning of the jury system.

The Supreme Court has emphasized that jurors are expected to follow judicial instructions as part of their oath and civic duty, reinforcing the legitimacy of this presumption. This presumption is embedded in criminal procedure doctrine and shapes appellate review standards, as trial judges are given broad discretion to determine whether an instruction is sufficient to cure prejudice. Appellate courts rarely overturn these determinations absent a clear abuse of discretion, reflecting deference to trial judges’ firsthand assessment of jury impact.

When a curative instruction is deemed inadequate to neutralize the prejudice, the law turns to a more drastic remedy: the mistrial. In some circumstances, courts conclude that striking evidence is insufficient, and prejudice cannot be cured through instruction alone, prompting a motion for a mistrial. A mistrial terminates the trial before a verdict and voids all proceedings, requiring a new trial with a different jury. Courts describe mistrials as a “drastic remedy” reserved for extreme circumstances, such as the improper admission of prior criminal history, inadmissible confessions, or inflammatory prosecutorial statements that directly implicate guilt. For example, the Supreme Court recognized in Bruton v. United States (1968) that a co-defendant’s confession implicating the defendant is so prejudicial that limiting instructions may be inadequate.

If a trial continues despite the admission of improper evidence, the issue often arises on appeal under harmless-error review. In Chapman v. California (1967), the Supreme Court held that constitutional errors require reversal unless the prosecution proves the error was harmless beyond a reasonable doubt. Non-constitutional evidentiary errors are reviewed under a less stringent standard, asking whether the error substantially influenced the verdict. Courts evaluate factors such as the strength of admissible evidence, the centrality of the improper evidence, and whether the error was isolated or repeated. This allows appellate courts to affirm convictions even when juries heard inadmissible evidence, so long as the court determines the error did not affect the outcome.

The assumption that jurors can disregard stricken evidence is often described as a legal fiction, but it serves practical purposes. Courts acknowledge that jurors cannot literally erase information from their minds, yet the legal system prioritizes procedural finality and judicial manageability over psychological certainty. By presuming juror compliance, courts avoid speculative inquiries into deliberations and maintain the efficiency and legitimacy of the jury system.

While the presumption is that jurors follow curative instructions, both courts and scholars recognize that exposure to improper evidence can continue to influence deliberations in identifiable ways. The Supreme Court has noted a confession is “probably the most probative and damaging evidence” a jury can hear, reflecting judicial awareness that some information leaves a particularly strong cognitive imprint and psychological weight..

Cognitive research helps explain why the presumption that jurors can disregard information is often unrealistic. Once jurors hear information, it often becomes part of the narrative they construct about the case. Research on jury reasoning shows that jurors tend to form early “story models” and evaluate later testimony through that lens, making later instructions to disregard difficult to implement. Improper evidence can influence jurors in several distinct ways. The first is anchoring , where early or dramatic information becomes a reference point that shapes all later evaluation. Next is the credibility spillover which stricken material, such as prior convictions, can continue to affect how jurors judge the defendant’s character for the remainder of the trial. Last is affective bias allowing emotionally charged testimony to shift jurors from element-based reasoning to intuitive judgment.

Courts implicitly acknowledge these effects when they describe certain evidence as a “bell that cannot be unrung,” concluding instructions are inadequate in extreme cases.  The doctrine of curative instructions therefore operates as a compromise, but it is hard to say if it actually works or not while at the hands of criminal defendants whose lives could be about to change forever. Striking evidence from the record is a routine but legally significant event in criminal trials. While jurors cannot literally unhear inadmissible testimony, courts rely on curative instructions, mistrial doctrine, and harmless-error review to manage prejudice and preserve trial integrity. Examining how courts address jury exposure to improper evidence reveals the doctrinal mechanisms that create tension with human cognition and the legal demands of fairness and finality in criminal adjudication.

Edited by: Katie Krawcheck