In this booking photo provided Thursday, May 7, 2009 by the Will County Sheriff's office in Joliet, Ill., former Bolingbrook, Ill., police sergeant Drew Peterson is shown.

JOLIET, ILL. - An Illinois jury on Thursday found former Chicago-area police officer Drew Peterson guilty of murdering his third wife, Kathleen Savio, in a case that received national attention and spawned a popular television movie.

Cheers erupted outside the courtroom in Will County, Illinois near Chicago after the verdict of first degree murder was read.

Peterson was convicted of killing Savio in 2004 during a contentious divorce and then staging her death to look like an accident. Savio was found dead in a bathtub, and the death was initially ruled accidental. Suspicions were raised when Peterson’s fourth wife, Stacy Peterson, disappeared in 2007.

“They got the murdering bastard,” Mitch Doman, the brother-in-law of Savio, said following the verdict.

Peterson remained impassive as the verdict was read and he was led from the courtroom in handcuffs.

The former Chicago-area police sergeant had waged a high-profile public relations campaign asserting his innocence both in the death of Savio and the disappearance of Stacy Peterson, who has never been found and is presumed dead. Drew Peterson is the only suspect in her disappearance.

“He was a thug,” prosecutor James Glasgow said of Peterson after the verdict. “He threatened people because he had a gun and a badge.”

During closing arguments on Tuesday, the prosecution had asked the jury of seven men and five women to use common sense and consider witness testimony that Peterson threatened Savio, tried to hire a hit man and said he could make her death look like an accident.

The defense argued that he should be acquitted because of the lack of physical evidence of his involvement in her death.

“It’s a very dark day in America when you can convict somebody on hearsay evidence,” said defense lawyer Joe Lopez.

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

The conviction followed several requests from the jury to the judge over two days of deliberations. Earlier on Thursday, the jury had asked the judge to clarify the meaning of “unanimous.”

Will County Judge Edward Burmila replied that unanimous meant “its common meaning” — that all 12 jurors would have to agree on a verdict.

Jurors declined to speak publicly after the trial. In a short, handwritten statement, the group said they took the responsibility seriously and solemnly. “After much deliberation, we have reached a decision that we believe is just.”

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

Glasgow said he will now aggressively review evidence that could lead to murder charges against Pederson stemming from the the disappearance of his fourth wife, Stacy.

Peterson will be sentenced in the Savio case on Nov. 26 and faces a sentence of 20-60 years in prison. His first and second wives have remarried.