A twist in high-flying mystery

seattletimes.nwsource.com — In the Northwest's most enduring mystery — who was D.B. Cooper? — about the only thing we've ever been certain of is that the legendary skyjacker was a he. What if he wasn't? "My wife says I'm two people," reads a 1969 letter to a University of Washington psychiatrist, as unearthed in a wild, so far unpublished book, "The Legend of D.B. Cooper. . .