yes. >> four years later, 1987, ivins filled out a medical history form at usamriid. asked about memory change. trouble with decisions. hallucinations. improbable beliefs and anxiety. ivins put a question mark. >> there was no follow-up. at no point did the army ever evaluate bruce ivins' mental fitness to handle anthrax. the approach was just to defer to his status as a ph.d. scientist, a trustworthy individual in their estimation. everybody knows that he wouldn't harm a flea. >> nancy haigwood isn't so sure. the stolen notebook. the vandalism. and the phony letter to the editor. it's enough for her to contact the fbi. >> i just thought, i just need to tell these people and they need -- they need to look into this. >> that there was a creepy side to bruce ivins? >> yes. a deceptive side. >> but for the next 4 1/2 years, her tip is low priority. >> we didn't know how to put it in any context. we had nothing to bring it together with. so at that time it sort of was tabled, if you will. >> a few months later, the fbi is making some progress. the anthrax letters, all wit

those tools and expertise were at usamriid. >> narrator: usamriid-- the u.s. army medical research institute of infectious diseases. located in maryland, usamriid is the center of the army's bio- defense effort. they took the powder there to the lab of one of the army's top anthrax vaccine experts, dr. bruce ivins. >> his reputation was that of an extraordinary microbiologist. he did the truly preliminary snapshot assessments of this material because he was so good at what he did. >> he was just fascinated with the way it was just like a mist. it was so light, you couldn't weigh it. it was very dangerous stuff. >> narrator: ivins and the scientists at the army's bio-lab said this was something new. unlike the wet anthrax they worked with, the powder was dry and very deadly. >> he was the first one to describe it as "energetic." the material literally would float and waft within the bag, for instance. and so, when anyone brought a hand near the bag, a lot of these spores would migrate towards the hand. >> narrator: they knew this highly floatable anthrax was so