Is it true that D.B. Cooper was a Boeing employee?

There is new evidence concerning the mystery of D.B. Cooper. A clip-on tie was found, which Cooper left behind on his seat after he hijacked a Northwest Orient Airplane in November 1971. A very powerful microscope used in their investigation found more than 100,000 particles on the JC Penny necktie. The particles included cerium, strontium, sulfide, and titanium.

One place where these elements were used was at Boeing for their high tech Supersonic Transport plane, developed in the 1960's and 1970's. Evidence suggests that Cooper was, in fact, a contractor or an employee for Boeing and he was an engineer or a manager in one of the plants.