Jury Selection

Before a jury trial begins, attorneys must select a jury from a panel of community members who have reported for jury duty. Rather than choosing jurors to sit on the jury, attorneys choose people to exclude from the jury. The attorneys may excuse anyone who exhibits demonstrable bias that would interfere with his or her ability to serve as a juror. Attorneys are also given a limited number of challenges that they may exercise for any reason except an attempt to exclude members of certain identifiable groups. When attorneys make their decisions to exclude potential jurors based on intuition or experience, the process is known as traditional jury selection. Scientific jury selection refers to the process where attorneys rely on social science surveys of community members to determine which types of jurors will be most favorable to their case.

Definition of Jury Selection

Jury selection is the process of choosing a petit jury of independent fact finders from a pool of venire members for a criminal or civil trial. Potential jurors are subjected to a system of examination known as voir dire, which allows judges and attorneys to obtain information about individual venire members. During voir dire, the judge and attorneys pose questions to individual jurors and the panel as a whole. Although the term jury selection gives the impression that the people are selected to remain seated on the jury, the process actually involves removing prospective jurors for a number of reasons. The Sixth Amendment of the U.S. Constitution gives defendants the right to be tried by an impartial jury. To fulfill the requirement of impartiality, jurors who harbor biases or cannot be fair to both sides are excluded from the jury through challenges. Individual venire members certainly have various expectations, beliefs, and experiences, but the legal system requires that members of the jury agree to set aside any preexisting biases and decide the case solely on the evidence. Although the Sixth Amendment states that jurors must be chosen from a representative cross-section of the community, this does not mean that the petit jury is representative of the community once the jury selection is finished. However, there are rules in place to protect against discrimination in the jury selection process, such as the Jury Selection and Services Act of 1968, which was created to ensure nondiscrimination in federal jury selection and services.

During jury selection, there are two types of challenges that attorneys can use to remove venire persons from the jury: challenges for cause and peremptory challenges. A challenge for cause is a request to remove a potential juror when there is reason to believe that he or she cannot serve as an impartial juror. When challenges for cause were first introduced, very few circumstances warranted their use. Only jurors who were related to the defendant by blood or marriage or those who possessed an economic interest in the case were excused for cause. Apart from those reasons, a juror could not to be removed from the jury for cause. In 1911, the Sixth Amendment was codified, and it provided both parties the right to challenge jurors for cause. Currently, the challenge for cause may be used to exclude prospective jurors who possess biases and are unable to follow the law in a given case. In addition, most states now acknowledge that potential jurors may be challenged for cause if they have a relationship with anyone involved in the trial, if the juror has prior experience with a similar case, or if an obvious bias or disability exists that would warrant removal. Judges are usually in charge of exercising the challenges for cause and striking out those people who appear to have a conflict with the case that cannot be corrected through juror rehabilitation.

The peremptory challenge is the second type of challenge offered to attorneys during voir dire. Peremptory challenges allow attorneys to remove a prospective juror without having to offer a reason for doing so. Attorneys from each side of the case are afforded a predetermined number of peremptory challenges with which to eliminate jurors and the number of peremptory challenges allowed varies depending on the state, the case, and even the judge. Initially, the peremptory challenge was permitted only in capital cases, and only the prosecution was allowed to use this device. Now, however, defendants are also afforded the use of peremptory challenges, and depending on the nature of the case, they may be allowed a greater number of peremptory challenges than the prosecution. Although the adoption of the Federal Rules of Criminal Procedure in 1946 attempted to reduce this prodefense advantage for capital, noncapital, and felony cases, the prosecution is still typically awarded fewer challenges than the defense. Once judges have struck ineligible jurors for cause, attorneys may still have concerns about prospective jurors that are insufficient to justify a challenge for cause. The peremptory challenge is intended to serve as a curative device for removing potentially biased jurors who cannot be removed for cause. For example, this type of challenge is appropriate to remove a juror who has avoided answering questions to remain on the jury, when the attorney suspects that the juror holds a bias that could not be demonstrated.

Peremptory challenges are legitimate provided that attorneys are not targeting people who are members of cognizable groups. According to the ruling in Batson v. Kentucky (1968), attorneys may not use peremptory challenges to exclude prospective jurors on the basis of race. The Supreme Court recognizes that excluding certain populations from jury service is a form of discrimination and jeopardizes the integrity of the justice system and has extended the Batson rule to include other cognizable groups such as gender, sexual orientation, and religion. Accordingly, if a peremptory challenge is contested by the opposing side, a reason for the removal must be stated, and the rationale for the challenge must be neutral to the cognizable groups. More commonly known as the Batson test, there are three steps taken to remedy the misuse of peremptory challenges. First, complainants have to demonstrate a prima facie case of discrimination, then the court needs to uncover the prejudice motives, and finally the attorney has to provide a valid reason for removing the prospective juror. Recently, the Supreme Court’s decisions have supported a more stringent enforcement of Batson’s requirements after a challenge was found to be racially motivated, in which a prosecutor excluded 10 of 11 qualified Black venire members from the panel. Some insist that the courts are unable to control the mandated use of peremptory challenges appropriately and suggest that they should be eliminated altogether to constrain attorney discretion. However, others argue that peremptory challenges provide parties with essential protection from the risk of partiality.

Many attorneys believe that the ability to sculpt a jury can have considerable bearing on the outcome of the trial. Currently, attorneys employ both traditional jury selection and scientific jury selection techniques to shape the jury. However, research is inconclusive as to which approach is more likely to achieve a desired outcome or result in a less “biased” jury. Traditional jury selection entails reliance on attorney experience and intuition to identify undesirable jurors, whereas scientific jury selection identifies unfavorable jurors by collecting case-relevant attitudes and demographic information from the community and analyzing it using statistical techniques. Each party then attempts to use peremptory challenges to exclude the prospective jurors who have been identified as possessing a bias, an opinion, a trait, or a characteristic that may be injurious to that party. Attorneys can use challenges to remove a potentially harmful juror; however, there are legal limitations to these challenges. That is, attorneys are not legally permitted to remove whomever they like for whatever reason. While the legal purpose of peremptory challenges is to eliminate jurors who may be biased, in practice, peremptory challenges are used for a variety of goals. Attorneys’ objectives may not necessarily be to obtain a fair jury but instead to obtain the jury that is most advantageous for their side of the case. In contrast, the court aims to seat a jury that best replicates the collective sentiment of the community and that is able to be fair to both sides of the case.

Traditional Jury Selection

Traditional jury selection refers to the strategies and techniques that derive from attorney experience and legal folklore. Traditional jury selection encompasses strategies such as previous experience with juries, common sense, expectations, intuition, and implicit stereotypes. Simply put, attorneys attempt to collect as much meaningful information as they can during voir dire and rely on stereotypes, instinct, hunches, and common sense to interpret that information. However, critics of this approach opine that in some cases, commonsense stereotypes can lead to opposite conclusions about the favorability of a particular of a juror. On the one hand, a prosecutor might assume that females are ideal jurors for a rape case because women are more inclined to identify and sympathize with the victim and are more likely to render a guilty verdict. On the other hand, a defense attorney might prefer female jurors on a rape case because women may need to believe that the victim put herself in a vulnerable position so that they can continue to believe that the world is just. Some civil attorneys assume that poor jurors should be avoided because they are more likely to make large awards of money due to their resentment of their own situation, whereas other civil attorneys assume that poor people would be less likely to award such large sums because they are not accustomed to that amount of money. These examples highlight the difficulties inherent in using stereotypes to formulate reliable assumptions about juror favorability.

Another factor that attorneys often consider during jury selection is juror nonverbal communication. It has been suggested that factors such as posture, pitch of voice, and willingness to express opinions go into the decision of who should stay on the jury and who should be removed. Other attorneys use information such as facial expression and perceived level of friendliness or extroversion to make decisions about prospective jurors. Although research has not proved traditional jury selection to be superior to other methods, it does not necessarily follow that the traditional approach should be abandoned. It is quite possible that in individual cases, attorneys may use their implicit theories about jurors based on years of experience to exercise peremptory challenges in their favor.

Scientific Jury Selection

Scientific jury selection refers to the use of community surveys and data analysis to yield probabilities that different types of prospective jurors will be favorable to a particular side. Scientific jury selection is a systematic method for identifying information that would be useful to elicit during the voir dire process and to rely on when deciding which jurors to challenge. The core of this approach assumes that different people who view the same evidence may render different verdicts and that verdict preference can be predicted by individual juror characteristics. This approach also assumes that attitudes and individual differences can be measured accurately; the attitudes themselves or proxies for the attitudes, such as demographic characteristics, must be discernable during voir dire. In addition, this approach requires that these attitudes and characteristics can ultimately be used to predict verdicts.

When conducting a community survey, trial consultants recruit a random sample of participants from the same pool from which an actual jury is being selected. These surveys are often conducted over the telephone by using a random digit dialing sampling technique. Respondents are asked questions that measure demographic characteristics, attitudes toward the legal system, knowledge of case facts, and case-relevant attitudes. Participants may also be provided with evidentiary information about the case. Participants are then asked to render a verdict. By using statistics to test for significant relationships between demographic characteristics, general attitudes, and case-relevant attitudes, trial consultants can educate attorneys about the likelihood that prospective jurors with certain attitudes or demographic characteristics will be favorable or unfavorable to their side. The techniques used during scientific jury selection must take into account the nature and scope of voir dire. For example, the information gleaned from a community survey that indicates that political affiliation is likely to be a strong predictor of verdict preference is helpful only if the judge allows the venire panel to be questioned about political affiliation. Because the judge determines which questions attorneys are allowed to pose to the venire panel, the scope of voir dire can vary widely. When only minimal voir dire is permitted, attorneys may not have any opportunity to pose any questions to the potential jurors, let alone questions that have been identified through the community survey to be predictive of verdicts. In more expanded voir dire situations, attorneys may be allowed to administer a questionnaire to the panel that could contain questions known to predict verdicts.

Individual Characteristics as Predictors of Verdicts

An abundance of research has been conducted on the relationship between individual juror characteristics and jurors’ verdict preferences. Research generally suggests that there is no single set of personality or demographic predictors that can be used for all types of cases. Unfortunately, those characteristics that are the most visible, such as gender and race, tend to be weakly correlated with verdict across cases. Although these characteristics are not good predictors in general, race and gender may be good predictors in specific types of cases in which these racial and gender issues are salient. For example, although juror gender is important when gender is an issue in the trial, such as in rape or sexual harassment cases, gender is not a stable predictor of verdicts in other types of cases. There is also evidence that personality characteristics such as authoritarianism, liberalism, and the need for social approval affect juror decisions. For example, jurors who score high on measures of authoritarianism are more conviction prone. It is arguable that group membership and political beliefs may have a greater influence on verdict judgments than race or gender because, unlike gender and race, people choose their affiliations. Jurors are affected by their cultural backgrounds, prior experiences, and personal affiliations. These factors influence the manner in which they understand and judge the details of the case. Social psychological research on in-group/out-group bias suggests that jurors may have an inclination to judge a witness who is similar to them as more credible and reliable than a witness who is dissimilar to them. However, research on the black sheep effect indicates that jurors may perceive in-group members more negatively than out-group members when the in-group member has committed a transgression. Therefore, the nature of the interaction between jurors’ group memberships and the defendant and witnesses’ group memberships will depend on the context of the particular case.

Although demographic and personality variables are not stable predictors of verdict judgments across cases, research suggests that case-relevant attitudes, such as death penalty attitudes or attitudes about business, predict verdicts. Studies on death penalty attitudes indicate that those who are pro-death penalty are more likely to render a guilty verdict than those who are against the death penalty. Finally, some research indicates that attitudes toward business and tort reform predict verdicts and awards in civil cases.

Efficacy of Jury Selection

A number of mock jury studies and field studies have been conducted to investigate the influence of jury selection strategies on jury verdict. In general, the research in this area indicates that the evidence accounts for the greatest amount of variance in juror verdicts, and that juror’s individual characteristics account only for approximately 5-15% of the variance. However, in cases such as capital cases where defendants have a possibility of receiving the death penalty, it can be argued that factors influencing this small percentage of variance become very important to study. Research has also demonstrated that case-relevant attitudes, such as attitudes toward the death penalty or attitudes toward the insanity defense, are better predictors of verdicts than general attitudes or demographic characteristics.

Investigating the utility of scientific jury selection is often done using mock jury simulations. Critics of this method argue that mock jury studies provide little practical utility for real jury selection because it is virtually impossible to replicate every aspect of a trial. Because participants know that their decisions in a study have no impact on a defendant in a real case, they may find it easier to render a guilty verdict because there are no real consequences for doing so.

Jury selection research has not conclusively established the superiority of one technique over another, in part because research in this area is difficult. To demonstrate that scientific jury selection is efficacious, it is necessary to establish its superiority over traditional jury selection and the random selection of jurors. However, some research suggests that traditional jury selection may result in a jury with attitudes similar to a jury composed of the first 12 jurors to be considered for the jury or a jury that is randomly selected from the jury pool. Nevertheless, instead of trying to identify which approach is more useful, it may be possible that a combination of an attorney’s experience and a trial consultant’s advanced research methodology would prove to be the most effective approach. Because the role of the jury is an integral part of the legal system, the process of selecting the jury is important and needs further empirical evaluation.


  1. Batson v. Kentucky, 106 S. Ct. 1712 (1986).
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  5. Kovera, M. B., Dickinson, J. J., & Cutler, B. L. (2003). Voir dire and jury selection. In A. M. Goldstein (Ed.), Handbook of psychology: Vol. 11. Forensic psychology (pp. 161-175). New York: Wiley.

Return to the overview of Trial Consulting in Forensic Psychology.