The Anthrax Files

Grant Leslie tells FRONTLINE she never had much confidence in the investigation following the anthrax attacks. "I just sort of felt like nothing during this entire process was really under control," she says.

In the days following the attacks, staffers Leslie and other staffers who tested positive for anthrax spores were put on Cipro. But Leslie, who says she's experienced no long-term side effects, was just ready to go back to work.

In the fall of 2001 envelopes carrying deadly Anthrax were delivered to U.S. Senate offices, network news divisions, and a tabloid newspaper. Five people were killed, many more infected and the nation was terrorized. Now, FRONTLINE takes a hard look at the FBI's investigation of the country's most notorious act of bioterrorism.

In the weeks after 9/11, Capitol Hill employees were on high alert. The Friday before she opened the anthrax letter, Grant Leslie, an intern in Sen. Daschle's office, received an unusual thank-you gift for the senator from a group of Alaskan Native Americans: a bag of fur. Capitol police were called but tests showed the gift was, in fact, animal fur.

"I remember thinking: 'Oh, this is from kids. This is going to be pretty cute. I can't wait to see what they're writing to Sen. Daschle about,'" Grant Leslie tells FRONTLINE. Upon opening the letter, white powder fell into her lap.

FRONTLINE takes a hard look at the FBI's investigation of the country's most notorious act of bioterrorism: the anthrax attacks of 2001. 10/11/2011