A petit jury -- also referred to as a trial jury -- consists of six to 12 members. This booklet explains the differences in civil and criminal trials, and provides insight into both the sequence of a trial and the role of a juror.Juries decide the fates of criminal defendants and the outcomes of civil cases and are essential to the overall administration of justice. Often the court will send a questionnaire to the jury pool to complete before the trial date in order to obtain basic information about the jury pool. The 2025 Jury Questionnaire is now available. Submit Questionnaire. Members of the jury, your function in the trial of this case is to reach a unanimous verdict. Chesterfield Jury Services is available Monday through Friday from 8 am to 4 pm, excluding holidays. The function of the Grand Jury is to determine whether there is probable cause to require the accused to stand trial. The Jury Questionnaire is one of the first steps in the juror selection process.