During jury selection in a criminal trial, the prosecution and defense have the opportunity to remove potential jurors whom they don't want on the jury.
Prosecutors and defense attorneys can use an unlimited number of "cause" challenges to eliminate jurors who aren't qualified, able, or fit to serve in the case. In using a cause challenge, the lawyer trying to remove a juror must give a reason to believe the juror won't be able to reach a fair verdict.
Lawyers can also use a limited number of imperative challenges to reject potential jurors without giving a reason for the rejection. Because lawyers don't have to give reasons for peremptory challenges, it's possible that they will use these challenges on the basis of a personal characteristic such as race.
While both the prosecution and the defense have the right to an impartial jury, the Equal Protection Clause of the Fourteenth Amendment protects the right of a criminal defendant to a jury selection process that is free from racial, ethnic, or gender discrimination. In Batson v. Kentucky, the U.S. Supreme Court created a process to determine whether the prosecution has removed a juror due to discriminatory bias. (476 U.S. 79, 89 (1986).) This process, called a "Batson challenge," involves the following steps.
If the judge decides that the prosecutor sufficiently explained the peremptory challenge, then the defendant must prove that the explanation is disingenuous. Otherwise, the judge won't find a Batson violation.
In order to show that the prosecutor's dismissal of a juror was discriminatory, a defendant must show that it was based on race, ethnicity, or gender. (It's not a violation for the prosecution to dismiss someone because of other characteristics such as religious denomination and social club membership.)
The Supreme Court has refused to specify what facts a defendant must present in order to make the above showing (called a "prima facie case") of discrimination. Rather, judges must evaluate all the circumstances when deciding whether it appears that discrimination is at play.
Evidence that a prosecutor has made biased statements during jury questioning, asked very different questions of minorities than of white jurors, or used a disproportionate number of peremptory challenges on minorities provides strong support for a prima facie case of jury discrimination. Other factors that will affect a judge's determination include whether:
If the judge accepts the defendant's prima facie showing of discriminatory intent, the prosecutor must give a neutral reason for excluding the juror in question.
In order to have a fair jury, both the prosecution and the defense can request the dismissal of potential jurors who show bias during the selection process. Thus, a prosecutor can legitimately seek dismissal of a potential juror who is likely biased and probably won't be impartial, regardless of that person's race, ethnicity, or gender.
Since there are many ways in which a potential juror may be biased, there are many legitimate reasons for challenging a juror. These include:
A potential juror's immaturity, lack of respect for authority, and lack of life experience are also legitimate bases for peremptory challenges.
After hearing from the parties, the judge must decide whether the defendant has proven that the prosecutor discriminated on an improper basis. The judge will evaluate the defense attorney's and prosecutor's arguments, including the persuasiveness of the prosecutor's explanation for the challenge.
If the prosecutor's reason for removing a juror is unrelated to the facts of the case, the judge will probably find that the challenge was improper. An example is justifying the challenge of a prospective female juror simply by observing that the defense challenged a number of men.
The judge is also likely to reject the prosecutor's explanation if it involves a gross mischaracterization of a juror's stated beliefs. This might occur if, for example, a dismissed juror in a capital case clearly expressed that he could impose the death penalty, but the prosecutor claimed that the juror was equivocal on the subject.
It's important to note that judges afford prosecutors considerable leeway in explaining challenges to jurors. If, for example, a prosecutor mistakenly attributed the statement of one juror to another, the judge may find that there hasn't been purposeful discrimination. A judge may also determine that a dismissal wasn't made for discriminatory reasons because the prosecutor accepted other jurors of the same race, ethnicity, or gender as the dismissed juror.
The exclusion of even one juror based on group bias is enough to constitute a Batson violation. The consequences of a violation depend upon when the defense proves it. If the defendant proves a Batson violation during jury selection, the usual remedy is to dismiss the entire panel of potential jurors, declare a mistrial, and select a new jury. Alternatively, a judge can decide to include the challenged juror in the jury, or to give the defendant additional peremptory challenges.
If the Batson violation isn't proven until after the defendant has already been convicted, then a court of appeal will typically overturn the conviction and grant a new trial.