Whodunit dept.; the anthrax culprit.(The Talk of the Town)

Barbara Hatch Rosenberg, a slight woman with short graying hair and deeply concerned hazel eyes, who works out of a small office at the State University of New York at Purchase, thinks she knows who was responsible for the anthrax attacks last October. Rosenberg is, to use the technical term, not chopped liver: she is a veteran molecular biologist and one of the world's leading experts on biological weapons. In 1998, she was one of a group of seven scientists who were invited to the White House to brief President Clinton on the subject. Yet her theory sounds like the plot of a conspiracy thriller, which is not usually true of experts' theories, especially on matters this grave.

On February 5th, Rosenberg posted an item on a Web site that she maintains for the Federation of American Scientists called "Commentary: Is the F.B.I. Dragging Its Feet?," in which she strongly implied that the F.B.I. was moving much more slowly in its anthrax investigation than it had any reason to. About the perpetrator she has in mind, she asked, "Does he know something that he believes is sufficiently damaging to the United States to make him untouchable by the F.B.I.?" It's important to note that, in addition to being an expert, Rosenberg has a political agenda: she is a committed campaigner for outside monitoring of biological-weapons laboratories. Although several local newspapers and the online magazine Salon ran articles on Rosenberg, it took a surprisingly long time -- nearly three weeks -- for her sensational Web posting to make an official impact, but on February 25th, after the Washington Times published a story that the F.B.I. had a prime suspect who sounded a lot like Rosenberg's, an array of top government officials, including Ari Fleischer, of the White House, and Robert Mueller III, of the F.B.I., were forced to address it -- which is to say, deny it -- publicly.

Here is Rosenberg's theory: All of the anthrax letters were sent by one person, a middle-aged man who had worked at the U.S. Army Medical Research Institute of Infectious Diseases, at Fort Detrick, Maryland, and who was familiar with the method of weaponizing anthrax devised by William Patrick III, the longtime head of bioweapons research at Fort Detrick. The perpetrator now works for a Washington-area subcontractor to the U.S. biological-weapons program. He is, as Rosenberg puts it, "not a normal person," and has a pattern of erratic behavior. She believes he received some kind of career setback after he left Fort Detrick that caused him to become "confused, upset, depressed, angry." He decided to ...