A Penn State history professor, who is writing a book about the disappearance of Jimmy Hoffa, doubts the deathbed confessions of a mob associate that became the plot of the book âI Heard You Paint Housesâ and the movie âThe Irishman.â At the end of his life, Frank âThe Irishmanâ Sheeran, a former Hoffa loyalist and self-professed mafia hit man, purportedly confessed to killing Hoffa in 1975 on the orders of mob boss Russell Bufalino of Kingston. âIâm very skeptical of Frank Sheeranâs claims,â professor David Witwer said during a virtual presentation on Hoffa hosted by Penn State Wilkes-Barre. âThere are lots of problems with Frank Sheeranâs account. There is no evidence he was the prolific hit man he claimed to be.â