It was arguably the most suspicious disappearance in American history: On July 30, 1975, James “Jimmy” Hoffa, former head of the International Brotherhood of Teamsters union and one of the most powerful and well-known men in America, vanished so quickly and so thoroughly that his vanishing would eventually become something of a punch line.

Hoffa was last seen in the back of a maroon Mercury leaving the Machus Red Fox, a Detroit restaurant where he was reportedly to meet mafiosos Anthony Giacolone and Anthony Provenzano. The FBI could never prove who killed Hoffa, but the presumption is that the mob hit him because he was trying to regain control of the union. In 2001, a DNA test would confirm that a hair found in the back of a car belonging to Giacolone’s son indeed belonged to Hoffa. Since many of the men suspected of conspiring to kill him are now dead themselves, that strand of hair may well be the closest anyone ever gets to finding his body.