Drew Peterson's son says his dad probably killed both his third and fourth wives.
Drew Peterson, a former Bolingbrook police sergeant, is serving a 38-year prison sentence for killing Kathleen Savio and he remains a suspect in the disappearance of his next wife, Stacy. Drew has not been charged in connection to Stacy's disappearance.
Stephen Peterson, 37, tells the Chicago Tribune he believes his dad "probably" killed Savio, and he's come to believe he killed Stacy Peterson, as well.
"Over time, you hear enough (from police). They can't all be full of s---," Stephen said. "I don't want to come out and say he did it ... but, I'm sure he did it."
Stephen says he does not know the details of what happened to Stacy, and that his dad still maintains his innocence to him.
-The Chicago Tribune contributed to this report