A hazmat worker is hosed off on Capitol Hill in October 2001 after anthrax-laced letters were sent to two senators. Five people ultimately died from the mailings, which were the work of Army scientist Bruce Ivins. (Ron Thomas / Associated Press)
Ivins mailed the anthrax-laced letters from a mailbox near this building in Princeton, N.J., which housed a Kappa Kappa Gamma office. He held a grudge against the sorority until he died. (Mike Derer / Associated Press)
Former Army virologist Steven Hatfill was the FBI’s prime suspect in the anthrax killings for five years. The government eventually cleared him and paid him a $5.8-million legal settlement. (Rick Bowmer / Associated Press)
The Frederick, Md., home of Bruce Ivins, where he overdosed on Tylenol at the age of 62. (Rob Carr / Associated Press)