NEW YORK (CBS/AP) Cassandra Cales is not going to stop until she brings her sister's body home, and on Friday she and more than 50 volunteers slogged through knee-deep mud and slush in suburban Illinois in the hopes of finding Stacy Peterson.
Peterson has been missing for almost two years. She's the fourth wife of former suburban Chicago police sergeant Drew Peterson, who has been charged with killing his third wife Kathleen Savio.
Police were not involved in the search behind an Ikea in Bolingbrook, Ill., just west of Highway 355, but the Chicago Sun-Times reported that the search was based on a tip that Cales received months ago that Drew Peterson was spotted walking in that area in the days following Stacy Peterson's disappearance.
The area had been too wet to search until now, and there are still areas where the searchers were unable to go.
"The water was up to our waists in some places, so it was pretty difficult work, but there are still places left for us to come back and check," Cales told the Chicago Tribune.
Friday's search did not turn up Stacy Peterson's body or any new clues to her disappearance. But her family says they will not be deterred.
Drew Peterson has been labeled by authorities as a person of interest in Stacy Peterson's disappearance, but he has not been charged.