SPRINGFIELD, Ill. (AP) — The use of hearsay testimony to convict former Chicago-area police officer Drew Peterson in the death of his third wife was proper, the Illinois Supreme Court ruled Thursday in upholding the conviction.

The high court, in a unanimous decision, found that hearsay testimony from Peterson’s missing fourth wife did not violate his constitutional right to confront his accusers.

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The 63-year-old former police sergeant from the Chicago suburb of Bolingbrook is serving a 38-year sentence in the 2004 death of ex-wife Kathleen Savio. He’s also serving a 40-year sentence after a conviction last year for soliciting the murder of the prosecutor who put him behind bars.

Savio’s body was found in a dry bathtub in 2004. Her death was initially ruled accidental, but the case was reopened after the 2007 disappearance of Peterson’s fourth wife, Stacy Peterson. Savio’s body was exhumed, an autopsy was conducted and her death was ruled a homicide. Peterson was then arrested for her murder in May 2009.

Prosecutors had no physical evidence tying Peterson to Savio’s death and no witnesses placing him at the scene, so they relied on hearsay — statements Savio made to others before she died and that Stacy Peterson made before she vanished.

Hearsay is any information reported by a witness that is not based on the witness’ direct knowledge. The U.S. Supreme Court has carved out exceptions for hearsay in cases where a defendant’s actions likely prevented the witness from testifying. Illinois passed a hearsay law in 2008 tailored to Drew Peterson’s case, dubbed “Drew’s Law,” which assisted in making some of the evidence admissible.

Peterson famously erupted during the 2013 sentencing hearing that followed his murder trial, screaming “I did not kill Kathleen!” before Will County Judge Edward Burmila sentenced him to 38 years behind bars. During the same hearing, Peterson told Will County State’s Attorney James Glasgow to “never forget my face. Never forget what you have done here.”

Then, when Peterson arrived at downstate Menard Correctional Center, he met a Satan’s Disciple known as “Beast,” whose real name is Antonio Smith. Smith turned out to be a snitch, who recorded Peterson talking about a plan to kill Glasgow.

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In one of Smith’s recordings, Peterson told his fellow inmate that “Stacy’s still alive, runnin’ around out there.” Smith replied, “Right.”

A Randolph County jury found Peterson guilty of the murder-for-hire plot last year, and a judge gave him another 40 years in prison. That took some of the wind out of the sails as Peterson appealed his murder conviction to the state’s high court.

Peterson lawyer Steve Greenberg told the Illinois Supreme Court in a June 2016 brief that, “the prosecution never presented physical evidence linking Peterson to Kathleen’s death, nor did it present any witness who placed Peterson at Kathleen’s home” the night of her death.

But the Attorney General’s office said injuries on Savio’s body appeared to come from a struggle — not a “single accidental fall while bathing.” It also said Peterson had the motive and opportunity to kill his third wife, had no alibi and “there was abundant evidence” that he had threatened her.

Stacy Peterson is presumed dead, though her body has never been found. Drew Peterson remains a suspect in her disappearance, but he has never been charged.

Peterson was transferred from a state prison in Chester, Illinois, to a federal prison in Terre Haute, Indiana, in February, after state prison officials cited concerns that he posed a security threat.

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(Source: The Associated Press and Sun-Times Media Wire contributed to this copy. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)