Authorities named a Bolingbrook, Ill., police sergeant a suspect Friday in the disappearance of his 23-year-old wife and announced plans to exhume the body of his ex-wife.

"Drew Peterson went to being a person of interest to clearly a suspect," said Illinois State Police Capt. Carl Dobrich at a press conference, adding that the case has shifted to a potential homicide case.

Peterson's ex-wife, Kathleen Savio, was found dead in her bathtub in 2004, and at the time, her death was ruled accidental. Peterson's current wife, Stacy, disappeared Oct. 29.

Click here for photos.

James Glasgow, the Will County State's Attorney, said there are strong indications that Savio's death was a homicide.

"There's no doubt in my mind that it wasn't an accident," Glasgow said.

Will County Coroner Patrick O'Neil, who reviewed Savio's autopsy, said earlier this week that there were aspects of her death that concerned him.

Click here to read Jamie Colby's blog: "Inside Drew Peterson's House."

The autopsy report found that Savio had a one-inch "blunt laceration" on the left side of her scalp, her "hair is soaked with blood" and she also had abrasions or bruises on seven different places on her body.

Family members have long suspected that Savio didn't drown accidentally in her bathtub as ruled by the coroner's office, Melissa Marie Doman, Savio's niece, said.

"I am all for it, along with the rest of my family, because something just was never right," Doman said. "I can't really say who, but someone did something. I don't think it was an accident."

When prosecutors learned of Stacy Peterson's disappearance, they reopened the investigation of Savio's death.

Stacy Peterson was reported missing Oct. 29 after she didn't arrive at a friend's house. Drew Peterson began dating Stacy when she was 17. They have two children, ages 2 and 4.

Drew Peterson recently told reporters that he believes his wife is alive and said he is being treated unfairly in this case.

Drew Peterson divorced Kathleen Savio, but financial issues hadn't been finalized when her body was found in her bathtub in 2004. There was no water in the tub.

The Associated Press contributed to this report.