Watch the two-hour special, "Riddle: The Search for James R. Hoffa," on Fox Nation. Fox Nation is a streaming subscription service you can access from your phone, computer and select TV devices. We've created a members-only destination for Fox News' most passionate and loyal fans featuring exclusive content, exclusive experiences and exclusive access. In this episode you'll hear from Jeff Hansen, a former law enforcement officer in Michigan, who spent years investigating what happened to Jimmy Hoffa. Jeff says Hoffa was cremated at a crematorium very close to the house in Detroit. The only crematorium he says was operating there in 1975. His book is "Digging for the Truth: The Final Resting Place of Jimmy Hoffa." Learn more about your ad choices. Visit megaphone.fm/adchoices