He was portrayed by the late Robert Prosky.
An older man, Flynn was an organizer for the Teamsters union. By the 1930s Flynn was the mentor and partner of the young union organizer Jimmy Hoffa. One night he was helping Hoffa with organizing laundries when Hoffa was accosted by a knife wielding Bobby Ciaro, whom Hoffa had inadvertently gotten fired when he revealed that he had ridden in Ciaro's truck cab. Seeing his partner in danger Flynn pulled his gun on Bobby and got him to stand down. The pair then convinced Bobby to come talk with them in their office, and hired him to help them with a job. Before leaving the office Flynn hold Bobby to give him the knife, and said if he wanted to go around he should get a gun and go "like a white man".
The job was to drive a truck while Flynn and Hoffa firebombed the Idle Hour Laundry, which had been disobliging and uncooperative when the two men tried to bring them into the teamsters. Something went horribly wrong and in addition to blowing up the laundry Flynn managed to set himself on fire.
Horribly burned Flynn was rushed to the hospital. Hoffa gave the police a cover story that Flynn thought he heard someone screaming in the laundry and ran in when it exploded. As Bobby backed up Hoffa's story a nun came out to tell the three men that Flynn was dying.
Hoffa and Bobby walked in to witness a priest finishing the last rites of the Roman Catholic Church. The priest then asked Flynn if there were any sins he wanted to confess before dying. Flynn tried to respond but was unable to get more than a couple grunts out before passing away. Years later, Bobby would start telling others that Flynn had told the priest off when asked if he wanted to make a final confession.
Shortly before his own death in 1975, Bobby and Hoffa remembered Flynn, with Hoff remarking that Flynn was from the good old days.