If the sniper (or snipers) does turn out to be a terrorist or terrorist-sympathizer, which I suspect (an easy way to damage the economy of the nation's capital and scare its inhabitants), the FBI will doubtlessly refuse to acknowledge it, just as they have never acknowledged that the murderer of the ElAl passengers at LAX was a terrorist.
Or like Hadayet, the LA Airport shooter, profile him as just someone suffering personal, financial issues.
Oh, and I'm starting to see the "can't be terrorism if someone doesn't take credit" angle lately again.