A witness against former Bolingbrook police officer Drew Peterson died in a truck crash Wednesday.
Walter Martineck was driving a delivery van when he rear-ended a semi trailer on I-55.
Martineck is the man who testified that Peterson’s brother helped Peterson carry a heavy blue barrel from his home.
Prosecutors have speculated that the barrel may have contained the body of Peterson’s fourth wife Stacy, who was last seen in 2007.
Peterson is serving a 38-year sentence for murdering his third wife, Kathleen Savio; he is the only suspect in Stacy Peterson’s disappearance.