Emotional Influence in the Courtroom: The Limits of Rule 403 and Ineffectiveness of Limiting Instructions 

Before any evidence can be introduced in court, it must first meet the criteria for admissibility under specific rules under the Federal Rules of Evidence.[1] However, even if evidence is admissible under these rules, it must still undergo a final check under Federal Rule of Evidence 403 (“Rule 403”), which allows the court to exclude evidence if its potential to cause unfair prejudice substantially outweighs its probative value.[2] When evidence is considered overly prejudicial but relevant, the court may still allow it to be introduced with a limiting instruction under Federal Rule of Evidence 105 (“Rule 105”), guiding the jury on how to appropriately consider it.[3] Yet, these instructions are often insufficient to counteract the emotional impact that such evidence can have on jurors, highlighting the ongoing challenge of balancing fairness with the admission of critical evidence in court.

Rule 403 allows for the exclusion of evidence when the risk of unfair prejudice substantially outweighs its probative value.[4] However, even with a limiting instruction under Rule 105, separating emotion from reason is a significant challenge.[5] By human nature, Jurors are driven by emotions, and the subconscious mind often forms conclusions before the conscious mind even begins to deliberate.[6] When emotionally charged evidence is presented, jurors may struggle to objectively evaluate the facts, despite being told to disregard their emotions. Limiting instructions does little to mitigate this response, as subconscious biases triggered by strong emotions are difficult to override. As a result, emotionally charged evidence can disproportionately influence their decision-making process, ultimately jeopardizing the fairness of the trial. This illustrates the difficulty in maintaining objectivity and fairness, even when such evidence is deemed relevant under Rule 403. 

Rule 403 does not permit the exclusion of evidence simply because it may hurt a party to a case, instead “[a]s a threshold matter, evidence is excludable only if it is ‘unfairly’ prejudicial, in that it has ‘an undue tendency to suggest decision on an improper basis.’”[7] Testimony adverse to an opposing party will always be prejudicial, but to be subject to exclusion, the prejudice must be unfair.[8] Evidence presents “unfair prejudice” when the introduction of the evidence provokes an emotional response or bias or has a tendency to lead the jury to unintentionally commit an inferential error. However, no court has developed a coherent definition.[9] The conditions of the trial and the group setting create some demanding characteristics that can lead to the use of cognitive shortcuts or unconscious biases that influence decision-making.[10] 

Experimental psychology has shown that exposing mock jurors to emotionally evocative images biases legal decisions against the defendant.[11] In a study where participants read a fictional trial transcript about a man stabbing and killing his ex-girlfriend, participants who saw graphic images of the crime scene, including the victim’s body, were more likely to report being affected by the images and felt the photos emphasized the crime’s severity, and were more than twice as likely to vote guilty compared to the those who did not see the photos.[12] In a similar study, involving weak circumstantial evidence, mock jurors who were informed that acts causing death were gruesome in nature rendered significantly more guilty verdicts than those who were informed that the acts causing death were non-gruesome.[13] While these graphic photographs may seem prejudicial, they can also serve to establish the defendant’s intent or state of mind at the time of the crime, offering crucial insight beyond painting the defendant in a negative light. But even if a court gives limited instructions and “restrict[s] the evidence to its proper scope and instruct[s] the jury accordingly[,]” such restriction does not always work out the way it is supposed to, and jurors make their subconscious choice.[14] 

The limiting instruction is a “recommendation to the jury of a mental gymnastic[s] which is beyond, not only their powers, but anybody’s else[,]” and “[n]ot every admission of inadmissible hearsay or other evidence can be considered to be [a] reversible error unavoidable through limiting instructions[.]”[15] The challenge lies in expecting jurors to compartmentalize emotionally charged evidence or disregard certain aspects of testimony while still being able to process the remainder of the information impartially. Human nature, with its inherent cognitive biases, makes it difficult for jurors to completely follow these instructions, as their subconscious often shapes their perceptions before conscious thought intervenes. Thus, while limiting instructions may provide a legal safeguard, in practice, they often fall short of mitigating the emotional impact of powerful evidence, leaving the fairness of the trial vulnerable to these psychological influences. 

SOURCES 

1 See e.g., FED. R. EVID. 404−05 (character evidence) & 801−04 (hearsay evidence).

2 FED. R. EVID. 403. 

3 FED. R. EVID. 105. 

4 FED. R. EVID. 403. 

5 See FED. R. EVID. 105 (“[T]he court, upon request, shall restrict the evidence to its proper scope and instruct the jury accordingly.” Id.). 

6 C.f. Roger Koenig-Robert & Joel Pearson, Decoding The Contents And Strength Of Imagery Before Volitional Engagement, SCIENTIFIC REPORTS, Mar. 5, 2019, at 1−14. Free choices about what to think can be predicted from patterns of brain activity 11 seconds before people consciously chose what to think about. 

7 See Old Chief v. United States, 519 U.S. 172, 193 (1997) (Advisory Committee’s Note on Fed. Rule Evid. 403, 28 U.S.C. App., p. 860). 

8 See id; Dollar v. Long Mfg., N. C., Inc., 561 F.2d 613, 618 (5th Cir. 1977) 

9 See Victor J. Gold, Federal Rule of Evidence 403: Observations on the Nature of Unfairly Prejudicial Evidence, 58 WASH. L. REV. 497, 498, 503−10 (1983). 

10 The Psychology of Jurors’ Decision-Making, PLAINTIFF MAGAZINE (Jan. 2018), https://plaintiffmagazine.com/recent-issues/item/the-psychology-of-jurors-decisionmaking#:~:text=The%20conditions%20of%20trial%20and%20the%20group%20setting,and%20group%20dynamic s%20can%20also%20play%20a%20role. 

11 Rachel C. Kush & Jane Goodman Delahunty, The Influence of Limiting Instructions on Processing and Judgments of Emotionally Evocative Evidence, 13 PSYCHIATRY,PSYCHOLOGY & LAW 110, 111 (2006). 

12 See Kevin S. Douglas, et al., The Impact of Graphic Photographic Evidence on Mock Jurors’ Decisions in a Murder Trial: Probative or Prejudicial?, 21 LAW & HUMAN BEHAVIOR 485, 485-501 (1997). 

13 See David A. Bright & Jane Goodman-Delahunty, The Influence Of Gruesome Verbal Evidence On Mock Juror Verdicts, 11 PSYCHIATRY,PSYCHOLOGY & LAW, 154, 161 (2004) (“A trial that involves the submission of gruesome evidence, such as oral or visual evidence of an exceptionally graphic and grisly quality, has the potential to arouse sympathy for the victim, instill sense of horror at the crime, and provoke a tendency to convict and to punish the defendant…[.]” Id. at 155.). 

14 FED. R. EVID. 105; see supra notes ix-x and accompanying text. 15 Nash v. United States, 54 F.2d 1006, 1007 (1932); Bruton v. United States, 391 U.S. 123, 139 (1968).