James Riddle Hoffa was the powerful and controversial leader of the Teamsters Union from 1957 to 1971, but he is now better known for his mysterious disappearance in 1975. Jimmy Hoffa was for years a giant in the world of labor unions, but he was often alleged to have ties to organized crime. After years of investigations by law enforcement, Hoffa was finally convicted of fraud and jury tampering in 1964 and served four years in prison before his sentence was commuted by President Richard Nixon. In 1975, while trying to regain power in the union, Jimmy Hoffa disappeared from the parking lot of the Machus Red Fox restaurant in Bloomfield Hills, Michigan. He was (and still is) widely assumed to have been killed by the Mafia. His body was never found, and in 1982 he was declared legally dead. In September of 2001, news reports claimed that DNA tests by the FBI had tied Hoffa to a car driven by his associate Charles O'Brien the day Hoffa disappeared -- suggesting that charges might still be brought in the case. That didn't happen, but rumors about Hoffa's final resting place still bubble up into the news every few years.