There is a therory that many of the top biochemist are being taken out that have the brains to fight a biological attack.
As far as this being the norm how many dentist are dying from blunt trauma and suicide?
If there is an direct attack on these bio-scientists it is more likely by a leftists that believes these type of scientists are better off dead. I hear it often from leftists but have not seen it take place yet.
About dentists death rates. a quick Internet search:
For some odd reason white male doctors have a high suicide rate.
http://www.straightdope.com/columns/010420.html