Do Peremptory Challenges Help Make a Jury More Impartial?

“Peremptory challenges, by enabling each side to exclude those jurors it believes will be most partial toward the other side, are a means of eliminat[ing] extremes of partiality on both sides… assuring the selection of a qualified and unbiased jury.” – Justice Scalia in Holland v Illinois.

Today, the Supreme Court of Canada heard arguments in the Pardeep Singh Chouhan case about the significance of peremptory challenges in jury selection. “Bill-C-75 — An Act to Amend the Criminal Code — came into effect on Sept. 19, 2019. The legislation modified the jury selection procedure under the Criminal Code by eliminating the right of the Crown and defence to make “peremptory challenges” — to object to a proposed juror without stating a reason”. (CBC) In doing so, the hearing touched on the issue of jury impartiality.

In its factum, the intervenor, the BC Civil Liberties Association, writes that juries should be diverse. “Diversity is no guarantee of impartiality. But race is—like gender, language, and province-of-origin— demonstrably linked to worldview… Despite the prevalence of racial bias, it can mitigated with greater diversity…” In its submissions the BCCLA argued that peremptory challenges promoted greater diversity and therefore impartiality.

In “Modeling the Effects of Peremptory Challenges on Jury Selection and Jury Verdicts” (2010), Roger Ford writes that “The remarkable thing about this debate is that there is almost no evidence that peremptory challenges have the positive effects that proponents describe and opponents concede.” Ford refers to a study done by Hans Zeisel & Shari Seidman Diamond, [The Effect of Peremptory Challenges on Jury and Verdict, 30 STAN. L. REV. 491 (1978)], it was found that lawyers are surprisingly ineffective at exercising peremptory challenges.

Ford continues to write that studies show that “attorneys rely on a small number of stereotypes or heuristics in exercising their challenges and, interestingly, that these characteristics differ across cultures.” In Australia, lawyers relied on different stereotypes than American lawyers. “For instance, Australian defense attorneys used peremptory challenges to strike younger, casually dressed potential jurors, contrary to the usual advice in the United States… While those in Australia tend to favour the prosecution, the other possible explanation is more troubling: that attorneys in the United States and Australia have just adopted different, opposing stereotypes without any real basis.” 

Ford notes a statistical finding that voir dire and peremptory challenges tend to “homogenize the composition of the jury that results”. Ford further argues that the more peremptory challenges a party has, the more likely the jury is to be ideologically and demographically the same.

Jury diversity matters because “jury deliberation would be useless if jurors did not influence each other. Ideally that influence would be in the realm of fact finding rather than bargaining…” Every juror has their own set of knowledge and life experience that inform their interpretation of the evidence. “Diversity of experiences increases the accuracy of jury fact finding by increasing the range of experiences that jurors will be able to use to evaluate the plausibility of the evidence.” By becoming more accurate in their fact finding process, juries may be able to be more impartial.

However, Ford points out that the idea that juries are more diverse before peremptory challenges only works if the pool of potential jurors is representative of the population. Having some peremptory challenges may “help exclude the occasional nutty juror, and they may help make defendants believe trials are fair.”

Ford remarks that technology may be harnessed to improve the use of peremptory challenges in jury selection. For example, counsel may wish to use a database that compares an individual potential juror to a comprehensive database of votes in a large number of trials. Then using that program to predict how often that potential juror would vote to convict.

The Supreme Court of Canada has found the legislation eliminating peremptory challenges constitutional and procedural in nature, with reasons to follow.