Recently investigators did a scientific analysis using a strand of hair found in the back seat of Charles O'Brien's car that was seen picking Hoffa up the day of the disappearance in 1975 (Seper 1). The hair's DNA structural components matched those of Hoffa's and raised suspicion on O'Brien. In accordance with Sepers's article, O'Brien claims that never was Hoffa in the car and denies knowing any additional information on the case.
Was Hoffa killed because Nixon wouldn't allow him to regain his seat, so out of revenge Hoffa had planned to expose Nixon's cover-up but stopped before he could? Or was it because mafia superiors wished keep Hoffa out of the reign?
Hoffa's successor Frank Fitzsimmons, a mild-mannered man, was now president of the Teamsters. Did, the mob leaders not wish to have Hoffa back in command? Fitzsimmons, who was much easier to manipulate than Hoffa and who was an approved guest of the White House, was much easier to work with. Illegal organized crime works were much easier to carry out because federal investigators were not keeping such a scrutinizing watch (Jimmy 2). Whether or not these reasons had something to do with his death, it still remains unknown, but legit motives nevertheless. As Ashenfelter and Schaefer point out, Nixon and Fitzsimmons could have helped close this unsolved mystery but because of the U.S. Justice Department superiors an end seems very unlikely. The Justice Department actually refused to make the two men testify before grand jury about their possible knowledge in the disappearance. After the disappearance, there were many stories published in the news about how Fitzsimmons had betrayed Hoffa and his role in the disappearance (Brill 15).