"Smart people (like smart lawyers) can come up with very good explanations for mistaken points of view."

- Richard P. Feynman, Physicist

"There is a danger in clarity, the danger of over looking the subtleties of truth."

-Alfred North Whitehead

May 2, 2011

Do Not Consider this Entry for Any Purpose

Jurors are often asked whether or not they can put aside what they heard or saw about a case and decide the case fairly and impartially based only upon the evidence presented at trial. In highly publicized cases, often jurors who had been exposed to pretrial publicity remain on a jury, after assuring all that they will remain “fair and impartial.” Jurors are also often instructed to “disregard that answer” or to use evidence in one way, but not for any other purpose, such as with “other-acts” evidence.

Are jurors able to follow these instructions? Empirical studies do not support the conclusion that they can. Researchers exposed mock jurors to different levels of two types of incriminating pretrial evidence—either factually oriented or emotionally oriented. They further measured the effect of time after exposure to that evidence on any bias resulting from the pretrial publicity. They found that the passage of time between the exposure to the pretrial publicity and the trial reduced any biasing effects of the publicity for factually oriented material. However, they did not find that this delay reduced the biasing effect of emotionally laden pretrial publicity.[i]

This research was replicated using videotaped and written pretrial publicity. No differences were found in the biasing effect of either videotaped or written pretrial publicity. Further, these researchers did not find a difference in the biasing effects of factually oriented pretrial publicity and emotionally laden pretrial publicity.[ii]

Research regarding trial instructions to disregard certain evidence, or to use certain evidence in limited ways is mixed. Research that looked at the disclosure of the defendant’s criminal history show that evidence of prior convictions did not necessarily increase the conviction rate. If the convictions were for similar conduct, then jurors were not able to keep it from influencing their verdicts. Some research shows that the deliberation process may assuage the effects of inadmissible evidence on juror bias.

One study looked at the type of instructions the judge used to inform the jury not to consider a statement of the defendant. A jury informed not to regard the statement because it was illegally obtained was less likely to follow the admonition than a jury informed not to regard the statement because the quality of the tape was too poor.[iii]

One finding in the research related to admonitions to disregard evidence is what is called the “back-fire effect”. The “back-fire effect” is when a jury pays more attention to evidence that they are instructed not to consider than if they were not so instructed. The explanation for the exclusion of the evidence appears to impact whether or not a jury will heed judicial instructions to disregard the evidence. There is some evidence to support the idea if the exclusion of the evidence is based on the unreliability of the evidence, such as hearsay, jurors will be more likely to heed the judicial instruction.

There are many psychological theories as to why jurors will not disregard, or are not capable of disregarding, inadmissible evidence. One of the more common and interesting theories is the production of a reactance in jurors. Reactance theory maintains that when a people are told that they cannot do something that they believe they should be able to do, they react to this prohibition by increasing their determination to engage in the behavior.[iv]

The research regarding the ability of a jury to disregard various inadmissible evidence shows that there is reason to believe that they often can’t. I don’t think this conclusion is anything that surprises anyone experienced in the court room. It does provide us with a warning to redouble our efforts to minimize a jury’s exposure to inadmissible evidence, and to not be misguided by fictions that believe that a limiting instruction can cure everything.



[i] Kramer, G.P., Kerr, N.L. & Carroll, J.S. (1990). Pretrial publicity, judicial remedies, and jury bias. Law and Human Behavior, 14, 4009-438.

[ii] Wilson, J.R & Bornstein, B.H. (1998). Methodological consideration in pretrial publicity research. Is the medium the message? Law and Human Behavior, 22, 585-598.

[iii] Kassin, S.M., & Sommers, S.R. (1997). Inadmissible testimony, instructions to disregard, and the jury: Substantive versus procedural considerations. Personality and Social Psychology Bulletin, 23, 1046-1054.

[iv] Lieberman, Joel D. and Arndt, Jamie (2000). Understanding the Limits of Limiting Instructions, Psychology, Public Policy and the Law, Vol 6, No. 3 677-711.

The views expressed in this blog are solely the views of the author(s) and do not represent the views of any other public official or organization.

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