Read other letters about this article
1. They worked at Ft. Detrick in the lab (access to raw anthrax).
2. They were anti-Arab and harrassed a co-worker based on religion and national origin. >>> Not afraid to ruin a life.
3. Could their beliefs and loyalties (however wrong) have led to a domestic terror attack on perceived liberals? e.g. ruin more lives (death).
4. Make the attack seem to come from Islamists (the letters).
Motive, means, opportunity.