Updated

The boyfriend of Drew Peterson's third wife testified Friday that he saw no bruises on her body in the days before she was found dead, a possible boost to the prosecution's case that her death was not accidental.

Kathleen Savio, the third wife of suburban Chicago police officer Drew Peterson, was found in her bathtub in 2004 with a gash on her head and several dark, red marks. Her drowning death was ruled accidental until police began investigating the 2007 disappearance of his fourth wife, Stacy Peterson.

Peterson, 58, is on trial for first-degree murder in the case of Savio. He has pleaded not guilty.

Peterson is also the prime suspect in Stacy Peterson's disappearance. The former Bolingbrook, Ill., officer claims Stacy, a 23-year-old mother of two, ran off with another man, but authorities believe she is dead.

On Friday, Savio's boyfriend, Steve Maniaci, was the first witness to take the stand on the eighth day of testimony. He said he began dating Savio around the time she and Peterson were getting divorced.

More On This...

Maniaci said he saw Savio naked three days before her battered body was found and that no marks had been apparent.

Savio's sister, Sue Doman, is also expected to testify Friday. Doman claims her sister told her that Peterson said he could kill her and make it look like an accident.

Click for more from MyFoxChicago.com