he also lived in Seattle and Bellevue....

in 2004 he was arrested for shooting out 2 construction workers tires during what he called an "anger fueled blackout"...

it also seems that he was an active responder in the 9/11 attacks in NY, while he was living there too, and that the PTSD from the events, could have taken a toll on him....

http://blogs.seattletimes.com/today/2013/09/washington-navy-yard-shooter-once-lived-in-seattle/