Updated

From nearly the moment the lead investigator stepped into the suburban Chicago area home where former policeman Drew Peterson's third wife was found dead in a bathtub, he treated her death as a tragic accident.

Illinois State Police Sgt. Patrick Collins testified Thursday and Friday he collected no forensics evidence — not fingerprints, unfinished drinks or clothes. He also let Peterson sit in on what may have been a vital interview with his fourth wife, the now missing Stacy Peterson.

Former Chicago police superintendent Richard Brzeczek says basic police work was not done during the initial investigation of Kathleen Savio's death, leaving prosecutors lacking in evidence and making harder to get a conviction.

Peterson has pleaded not guilty in Savio's 2004 death.