BOLINGBROOK, Ill. — Former police sergeant Drew Peterson, long suspected in the 2007 disappearance of his fourth wife, was charged Thursday with murdering his third wife, whose 2004 death had been deemed accidental before authorities revisited it once Stacy Peterson vanished.

Will County prosecutors and Illinois State Police planned an evening news conference to discuss a murder indictment issued against the former Bolingbrook police officer in the death of Kathleen Savio.

Peterson was arrested Thursday evening during a traffic stop in Bolingbrook, said Chuck Pelkie, spokesman for Will County state's attorney.

Authorities declined to immediately release further details.

Savio's body was found in an empty bathtub. Her death was originally ruled an accidental drowning but authorities later said it was a homicide staged to look like an accident.

Savio's family has long voiced suspicions about the circumstances surrounding her death, especially after the October 2007 disappearance of Stacy Peterson, then 23.

Peterson, 55, is a suspect in the disappearance but has not been charged in that case. He has repeatedly said he thinks Stacy Peterson ran off with another man.

Peterson's attorney, Joel Brodsky, said in an email Thursday he was on his way to New York and referred messages to Peterson's publicist, Glenn Selig. Selig said only that he could not confirm Peterson's arrest.

Savio's 73-year-old father, Henry, said Thursday that an arrest should have been made long ago.

""I was never pleased with the (coroner's finding of suicide) from the beginning," he said.

In more than a year and a half since Stacy Peterson's disappearance, Drew Peterson has been under a media microscope, and at times he has seemed to relish the attention.

This week Selig said Peterson was interested in a job offer from a Nevada brothel that is the setting for the HBO reality show "Cathouse." An HBO spokeswoman said the network would sooner cancel the show than allow Peterson to appear on it.