D.B. COOPER HIJACKING UPDATE: The FBI closed the 1971 airplane hijacking and ransom case in July 2016. The hijacker parachuted from the plane, with the cash. However, amateur sleuths have turned up an intriguing lead.
The three amateur scientists have found rare-Earth elements on the JCPenney tie the infamous skyjacker left behind when he jumped out of a commercial airplane on a blistering night in 1971, with $200,000 in unmarked bills, a parachute, and a raincoat. The sleuths say the elements could indicate Cooper was an engineer or manager in the aerospace industry.
This is an informative article with a succinct summary of the crime.