BOSTON — A decades-long search for a fugitive charged in the 1980 killing of a Pennsylvania police chief came to a dramatic end Friday as authorities positively identified remains found buried in a Massachusetts yard as the man they have long suspected in the fatal shooting.

Donald Eugene Webb was one of the longest-tenured fugitives on the FBI’s Ten Most Wanted Fugitives list, appearing there from 1981 to 2007. Authorities believe Webb shot and killed Saxonburg Police Chief Gregory Adams in December 1980 after Adams pulled him over for running a stop sign.

Webb, then 49, was a jewelry thief from Massachusetts with connections to the New England mob. Police believe that when Adams stopped Webb’s car, he was in Saxonburg, outside Pittsburgh, to case a jewelry store he planned to rob.

Webb disappeared after the killing, but his car was found two weeks later in a parking lot in Warwick, Rhode Island. Within weeks of the killing, a federal arrest warrant was issued for Webb after he was charged with unlawful flight to avoid prosecution and charged in Pennsylvania with first-degree murder.

Police were led to Webb’s body Thursday by his ex-wife, Lillian, who showed them where he was buried in her back yard in Dartmouth, Massachusetts. Prosecutors in both Massachusetts and Pennsylvania confirmed to The Associated Press on Friday that authorities have agreed not to prosecute Lillian Webb in the investigation.

The FBI said investigators believe Webb died about 17 years ago. Gregg Miliote, a spokesman for the Bristol County District Attorney’s Office in Massachusetts, said Webb’s cause of death has not yet been determined, but it “does not appear his death was the result of a violent act.”

The police chief’s widow, Mary Ann Jones, said she is livid that Lillian Webb kept her ex-husband’s whereabouts hidden for years, as Jones and her two sons struggled with their loss and the thought that the killer was still at large.

“I guess I’m angry at her at this point because she could do that to my family – hide him for years and then bury him so we never know,” Jones said. “Why hide him? Why not allow us closure?”

Lillian Webb could not be reached for comment Friday.