Dolores Miller thought it was "a weird coincidence" that her father, Delaware union leader Frank Sheeran, went to Detroit to attend a wedding the very weekend in July 1975 that his pal, teamsters leader Jimmy Hoffa, vanished from a restaurant in the area. "I suspected my father knew what had happened," says Miller, 49. "But I never put the gun in his hands."

Now Sheeran has done that himself. According to a new book by retired prosecutor Charles Brandt, I Heard You Paint Houses (Mobspeak for "I heard you whack guys"), Sheeran confessed late in life that after getting the sort of offer you don't refuse from Pennsylvania crime boss Russell Bufalino, he lured Hoffa, 62, to a Detroit house, then shot him "twice at a decent range...behind his right ear."

Some experts question the credibility of Sheeran, who was 83 when he died in December. In the book, for example, he also takes credit for the 1972 slaying of mobster Joseph Gallo. But possibly supporting his account of the Hoffa hit are stains on the Detroit home's floorboards that police forensic experts pried up May 28 for DNA analysis. In addition, local prosecutor David Gorcyca wants to interview witnesses before a sitting federal grand jury. "I want to further corroborate Frank Sheeran's story," he says, "or discredit it."