Drew Peterson is already charged with first-degree murder in the 2004 death of his third wife, Kathleen Savio, whose body was found in a dry bathtub at her home. He's pleaded not guilty to the charges. Jury selection in the trial is set for next month. He's being held in isolation at the Will County Jail.
State police and other law enforcement agencies were searching rural land "thick with timber" near Peoria for signs of Stacy Peterson, said state police Master Sgt. Tom Burek.
Rains have reduced the land to a "muddy mess" meaning that parts are inaccessible by vehicle and investigators have had to comb the area on foot, Burek said.
He wouldn't say when the search began or how large the search area is. He also wouldn't confirm where the lead came from or how credible police thought it might be.
"We follow up on every lead," he said.
Investigators have pursued several tips about Stacy Peterson's disappearance over the years, including sending divers into murky Chicago-area waters.
Drew Peterson's attorney, Joel Brodsky, called the most recent search "patently ridiculous."
"Drew's position from day one has always been that she ran off with another man, because that's what she told him," Brodsky said. "This is just another in a long line of unsubstantiated rumors about Drew Peterson, all of which have proved to be false."