This April 12, 1971 file photo shows James 'Jimmy' Hoffa (L) former president of the Teamsters union, and his son James P. Hoffa. - 

This final note today: Jimmy Hoffa was last seen in 1975, and now a convicted mobster says he's "certain" he knows where Jimmy Hoffa's body is buried -- in a Michigan field some 20 miles from where he was last seen in 1975.

The former Teamsters president is widely believed to have been killed by the mob, but proving it could cost a whole lot. The feds spent $225,000 digging up a barn looking for Hoffa in 2006, according to DOJ records. That doesn't include the salaries or travel costs of the FBI agents who participated in the dig.

And yeah, they didn't find him.

Follow Kai Ryssdal at @kairyssdal