Alawyer who strikes a potential juror due to a gut feeling that the person will not be sympathetic to a client is utilizing

During jury selection process,  attorneys from each side take turns in picking the jurors they believe will favor their position and not their opponent's  A lawyer who strikes a potential juror due to a gut feeling that he will not be sympathetic to a client is utilizing the so-called peremptory challenge.  A peremptory challenge is a practice used to excuse potential jurors without providing a reason why.    The rationale behind allowing peremptory challenges is to give the attorneys the chance to pick the best jury for each case,  resulting to a well-balanced jury.

when comparing the cases, what similarities are there in the cases that suggest one person committed these murders?