A jewel thief-turned-suspected murderer spent 37 years evading the FBI. He may have spent 20 of those years hiding in a secret room in his wife’s house—before someone buried him in her backyard.

Donald Eugene Webb was wanted for a jewelry heist when Gregory Adams, the police chief of quiet Saxonburg, Pennsylvania, pulled over Webb’s car for a traffic stop on Dec. 4, 1980. Webb reportedly gave Adams a New Jersey license belonging to a dead man whose widow Webb had remarried. Investigators believe the fake ID raised Adams’ suspicions. Fearing arrest, Webb allegedly fired two shots into the police chief’s chest. Adams died on the way to the hospital.

Webb disappeared without a trace—until investigators found his body buried on his wife’s property in North Dartmouth, Massachusetts, on Friday, nearly 37 years after Adams’ murder.

Webb should have been an easy fugitive to find. The alleged killer had a scar on his right cheek, his own name tattooed on his right hand, and a woman’s name—not his wife’s—tattooed across his chest, the FBI said in 1981, when the bureau first added him to its Ten Most Wanted fugitives list.

“The FBI said Webb is known for his flashy dress, love of dogs and his reputation as a big tipper… a professional jewel thief and master of assumed identities,” the Associated Press reported at the time.

Webb, then in his early fifties, had already racked up an impressive rap sheet of robberies, and had served at least two prison sentences for botched bank heists in New York and Massachusetts. Investigators believed him to be a member of the mob-linked “Fall River Gang,” which allegedly helped him sell stolen jewels.

But after Adams’ murder, Webb had a head start on investigators. Two weeks after the slaying, police would find Webb’s rental car abandoned outside a Rhode Island motel, with Webb’s blood coating the floor. The FBI kept Webb on its Top Ten Most Wanted List for 26 years, until 2007, when the then-senior citizen was replaced by more dangerous suspects. FBI investigators speculated that Webb might have died during his decades on the lam.

“Some investigators think Webb was killed years ago because he brought unwanted attention to the [Fall River] gang,” the Associated Press reported at the time. “Others think he died because he didn’t take care of himself.”

But when the FBI announced a renewed effort to find Webb in 2016, the lead investigator believed the fugitive was still alive, Rhode Island’s WPRI reported at the time. And this time, investigators were working off a new clue: a secret room they’d discovered hidden in Webb’s wife’s home.

Webb’s wife Lillian lives in a tidy home on a residential street in North Dartmouth, Massachusetts. While searching the home upon revisiting Webb’s case, FBI investigators found a hidden room inside a closet, which could be “accessed through a closet in Mrs. Webb’s house,” Thomas King III, an attorney representing Adams’ wife told The Daily Beast.

An FBI agent told Adams’ wife about the room in June 2017, shortly after which she filed paperwork in preparation for a civil suit against Webb’s wife, accusing her of hiding Webb in the secret room during his long stint on the run. Inside the room was a clue that suggested Webb had hidden there.

“In the secret room (which locked from the inside), was a cane,” King said. “The cane was significant because it has long been believed that Chief Adams shot Webb in the leg, and that he may have needed a cane to walk.”

But Webb’s final fate was revealed on Friday, when investigators excavated Webb’s wife’s backyard. Beneath the hedge-lined yard was Webb’s body, which had lain dead for approximately 17 years, the Office of the Chief Medical Examiner of Massachusetts determined.

His exact cause of death, or how he evaded capture for 20 years remain unknown. But the mystery that had dogged Saxonburg police for decades has finally reached some kind of conclusion, the small town’s new police chief said.

“We’re beyond proud of the efforts by the FBI, Pennsylvania State Police, and Massachusetts State Police in doggedly working to resolve this case,” Saxonburg Police Chief Joseph Beachem said in a statement.

“The biggest question in the history of Saxonburg has been answered. Our thoughts are with the family, and we hope this eases their minds, if even only slightly. While the hurt will continue, at least doubt about what happened that day has been eliminated.”