Weren't the DC snipers from WA?
Only in that that is where they obtained the rifle. The older guy was (I think) originally from Baton Rouge, La. and the youger one was a "furriner" from one of the Caribbean Islands (Puerto Rico/Dominican Repub.??).
As I recall, the older one married the younger one's mother and got her to the states, where she left him and ended up in or around Tacoma. He followed her up (stalking), and got the younger guy to join him.
There are also strong indications that there was some "Muslim theology" involved.