During jury selection, lawyers have the ability to ask potential jurors to leave the jury and not be part of the trial, and they do not have to you are a potential juror and the lawyers asks you if you know any of the parties in the case—the victim, the defendant, or the lawyers. she asking you this question

to determine if you can be impartial as a member of the jury
to find out if there is a reason to kick you off the jury
to determine how to plan her opening statement to the jury
to find out if there is reason to believe the defendant may be lying