Anthrax suicide: suspect or victim?

A possible suspect for the anthrax attacks in 2001 has apparently committed suicide. He was a researcher at USAMRIID working on biodefenses such as a vaccine against anthrax. He was being quietly investigated by the FBI, which is not surprising given what happened the last time a suspect's name was leaked to the public.

He had access to anthrax and lived within 200 miles from where the anthrax-tainted letters were apparently mailed from, so it's feasible that he was indeed the culprit, although not enough details are public to even form an opinion if it really could have been him. But if he was indeed the culprit, in which case I apologize to the FBI for saying they didn't have a clue, what would have been his motive? Was it a cynical attempt to get increased funding into anthrax research? Was it a severely misguided attempt at venting his frustrations? Or was he just a patsy for certain government agencies trying to ferment a climate of fear?

On the other hand, it's quite possible he's innocent. Losing his job and being harassed by the FBI could have made him depressed enough to commit suicide. Of course, this is assuming that it was suicide. For all we know, it could have been murder by the actual culprits of the 2001 anthrax attack, killing a known suspect and making it look like suicide in order to halt any further investigations.