Dateline: April, 2021, Issue 3

Does judicial rehabilitation in voir dire about the insanity defense reduce juror bias?

During voir dire, judges frequently attempt to rehabilite potential jurors who express an inability to be impartial. In an insanity defense case, jurors opposed to a not guilty by reason of insanity (NGRI) verdict are often asked if they can put aside their personal feelings about the insanity defense and base their decision on the evidence and the law.

Crocker and Kovera (2010) examined whether judicial rehabilitative questioning during voir dire in an insanity defense case reduced the influence of juror bias on verdict judgments in a simulated trial. Over 120 mock jurors completed an online juror questionnaire prior to arriving at a mock courtroom. Half of the jurors reported on the juror questionnaire that rendering a verdict of not guilty by reason of insanity (NGRI) is never appropriate, while the other half believed situations exist in which NGRI is appropriate. Most jurors, even those who found NGRI verdicts sometimes appropriate, had reservations about the insanity defense.

After mock jurors arrived at the staged courtroom, an actress playing the role of the Judge conducted voir dire for an insanity defense case. The mock jurors stated basic demographic information publicly, and then the Judge individually and privately questioned each juror at a sidebar at the bench. In this private questioning, the Judge asked all jurors questions about reading and television viewing habits, with 50% of the jurors also undergoing rehabilitative questioning about their views of the insanity defense.

All mock jurors then were told they had been empanelled on the jury, watched a videotape of an insanity defense trial, and then rendered individual verdicts.

Not unsurprisingly, jurors who believed the insanity defense was never appropriate voted guilty more often and with higher confidence than jurors who felt NGRI was sometimes appropriate. However, and surprisingly, juror rehabilitation about NGRI beliefs (a) reduced perceptions of defendant guilt and juror bias against the insanity defense and (b) for both jurors opposed to and accepting of NGRI verdicts. Mock jurors in a follow-up experiment who watched the Judge engage in rehabilitative questioning about NGRI beliefs in a public group voir dire also had lower expectations that the defendant would be convicted.

Judicial rehabilitation reduces bias against the insanity defense, but jurors with pre-existing opposition to NGRI verdicts remain more opposed than those who believe it sometimes is appropriate.

Source Crocker, C.B. & Kovera, M.B. (2010). The effects of rehabilitative voir dire on juror bias and decision making. Law and Human Behavior, 34(3), pp. 212-226.