Peremptory challenges are used by both prosecution and defense to shape juries by dismissing potential members without explanation or apparent cause. Most prosecutors' offices have not devised any formal procedures for the exercise of peremptory challenges; thus, the process by which prosecutors reach a decision to accept or reject a juror is for the most part unknown. This project was designed to uncover the type and amount of information important to Massachusetts prosecutors when faced with the opportunity to exercise the peremptory challenge. The research also analyzes the varying weight assigned to information topics, the amount of information needed to make a decision, and whether the characteristics of the crime or offender influence challenges. Further, prosecutorial 'styles' of information use are explored. Twenty prosecutors randomly selected from four counties in and around the Greater Boston area were asked to challenge described jurors in two cases where the charge and the defendant's characteristics were presented. After their initial decisions, the subjects were supplied with some additional information and told they could change their decisions based on the new information. While the findings did suggest the existence of information-processing styles, it did not show uniformity of decisions in relation to these styles, suggesting that the challenging of a juror is a highly individualistic process. The test did clearly demonstrate that race is treated differently by the majority of the subjects when a black in contrast to a white is on trial. The project shows a need for more extensive research in this area. Tabular data and 84 footnotes are provided.