Former police sergeant Drew Peterson is pictured in this booking photo, released by the Will County Sheriff's Office on May 8, 2009. REUTERS/Will County Sheriff's Office/Handout

CHICAGO - A judge on Thursday sentenced former Chicago-area police officer Drew Peterson to 38 years in prison for the murder of his third wife, whose death initially appeared accidental until Peterson’s fourth wife disappeared.

Will County Judge Edward Burmila sentenced Peterson after rejecting a plea for a retrial in the death of Kathleen Savio. He had faced a maximum of 60 years in prison.

Peterson was convicted last September of killing Savio in 2004 during a contentious divorce and then trying to make her death look like an accident. Savio was found dead in a bathtub, and her death was at first ruled accidental.

Suspicions were raised when Peterson’s fourth wife, Stacy Peterson, disappeared in 2007.

After the sentencing, the former police officer’s defence team told reporters they would appeal the conviction, saying the trial had been riddled with problems.

"I did not kill Kathleen!" Peterson screamed in the courtroom Thursday.

“They changed the rules to convict him, they changed the evidence,” said attorney Steve Greenberg. “They changed everything.”

The Illinois state legislature passed a law, dubbed “Drew’s law,” in response to the case, loosening requirements for circumstantial evidence.

Peterson, who was a police sergeant in Bolingbrook, Illinois, had waged a high-profile public relations campaign asserting his innocence both in the death of Savio and the disappearance of Stacy Peterson, who is presumed dead. He is the only suspect in her disappearance.

Witnesses testified in the trial that Peterson threatened Savio, tried to hire a hit man and said he could make her death look like an accident.

Prosecutor James Glasgow, asked what he was thinking when looking at Peterson in the Joliet courtroom on Thursday, said: “You’re a cold-blooded murderer and I’ll stare you down until I die.”

Peterson’s first and second wives have remarried.

The Peterson case was the inspiration for a popular Lifetime television network movie, “Untouchable,” based on the case, starring Rob Lowe.