Webb was being sought in connection with the murder of Police Chief Gregory Adams of Saxonburg, Pennsylvania on December 4, 1980.
According to a release from the FBI, on New Year's Eve 1980, 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 for the death of Chief Adams.
She led investigators to her home in Dartmouth, Massachusettes, where human remains believed to be Webb's were found, the AP report said.
The FBI said in a statement late Thursday that they are in the process of determining if the remains belong to fugitive Donald Eugene Webb.
Webb became one of the longest-appearing fugitives on the FBI's Ten Most Wanted list.
The current police chief in Saxonburg drove 11 hours to be in MA for the search. Webb was a career criminal living in New Bedford, Massachusetts, at the time. In addition, Jones told the AP, agents found a "secret room" in the home with a cane.
The FBI has offered $100,000 for information leading to Webb's capture.
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"No. No. The man got away with murder", Adams Jones said.
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.
"Although it's unfortunate Mr. Webb will never be brought to justice to pay for his crimes, we're hopeful the family can find some closure in knowing that this alleged murderer has been located", he added.
Records from the Bristol County Probate and Family Court show Lillian Webb divorced her husband in September of 2005. After all these years, Webb's remains have been found in the backyard of his ex-wife's home in MA.
Police have discovered what appeared to be human remains behind a home with connections to the decades-old, unsolved slaying of a Pennsylvania police chief, authorities said.
King said Jones and her sons agreed to drop the lawsuit so the Butler County District Attorney's office could work out the immunity deal. The cause listed in the paperwork is "desertion".