There is a show on History now, Brad Meltzer's Decoded. It's quite good. It follows a team of investigators who try to determine the meanings behind various symbolism, alleged secret codes and conspiracies.
They did a fascinating episode on D.B. Cooper, the famous 1971 skyjacker that vanished into history. They made a good case against the guy profiled, Kenneth Christiansen (who died in 1994). He worked for the same company that ran the plane Cooper hijacked, he suddenly came into some money after the hijacking (he paid cash for a new house). In his former house, the team found a hidden compartment above his old bedroom, although now empty, it could have been used to hold money. I'm surprised the FBI hasn't taken an interest in this. Of course, since Kenneth Christiansen is now deceased, he can't be prosecuted, but it would be nice to close the case.
This show belongs on History more than Ice Road Morons and Ax men.