A spokeswoman for the family of Stacy Peterson -- Peterson’s missing fourth wife --- expressed frustration at today’s motion for mistrial, saying she believes it is not the last time Peterson’s attorneys will be calling foul. “You’re always going to hear the defense crying mistrial -- that’s like their only defense right there,” Pamela Bosco said after court adjourned for the day. “I don’t think this is the last time we’ll be hearing this.” The defense had unsucessfully sought a mistrial on Tuesday. Boscoe said she was initially nervous at the second apparent close call for the prosecution today. “But …