One notable case in point was the suicide of Dr Bruce Ivins, senior biodefense researcher at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) in Fort Detrick, Maryland.
By 2008, Ivins had found himself on the FBI's short list in the Amerithrax[1] investigation. No autopsy was ordered[2], due to the medical examiner's blood tests which revealed an overdose of acetaminophen and codeine.
[1]http://en.wikipedia.org/wiki/2001_anthrax_attacks
[2]http://www.bloomberg.com/apps/news?pid=newsarchive&sid=aKQxd...
http://onlinelibrary.wiley.com/doi/10.1002/hep.20948/pdf