JOLIET — The man who led the investigation into the death of Drew Peterson's third wife is expected to testify as the former Illinois police officer's murder trial enters its sixth day.

Retired Illinois State Police Sgt. Patrick Collins will testify Wednesday as prosecutors attempt to show the investigation he led after Kathleen Savio was found dead in her bathtub in 2004 was botched.

At a hearsay hearing in 2010, Collins said he believed Savio's death was an accident from almost the minute he stepped into her home.