Dr. Steven J. Hatfill said he understood that his expertise in germ warfare would force him to answer questions about last fall's attacks, but said he had never worked with anthrax and there was not a "shred of evidence" he was involved.
"I am a loyal American and I love my country," Hatfill told reporters outside his lawyer's office. "I have had nothing to do in any way, shape or form with the mailing of these anthrax letters."
Hatfill, who had an American flag pin affixed to his lapel, said he had cooperated fully with authorities only to have what he called defamatory information about him leaked to reporters. He said he understood that authorities and the media had to consider his potential involvement after the letters killed five and sickened more than a dozen people.
"This does not, however, give them the right to smear me and gratuitously make a wasteland of my life in the process," he said.
Law enforcement officials have described Hatfill, 48, as "person of interest," not a suspect, and that he is one of about 30 people being examined.
On Sunday, a law enforcement official close to the case said the scientist has not "received any more attention than any other person of interest in the investigation."
Hatfill's name is the only to have emerged publicly in the investigation.
Since then, several questions have surfaced about Hatfill, including what appear to be exaggerations on his resume, his involvement fighting for white rule in the former Rhodesia and whether he lost his security clearance while working for a defense contractor.
Hatfill took no questions after his statement. His lawyer declined to answer questions about Hatfill's past.
Hatfill emphasized that his background is in the study of viral diseases such as Ebola, not bacterial diseases such as anthrax.
He said he was routinely vaccinated against anthrax because of his work at the U.S. Army Medical Research Institute at Fort Detrick, Md., once home to the U.S. biological warfare program and repository for the Ames strain of anthrax that was used in the attacks. But he said he had not been inoculated since 1999 and had been susceptible to anthrax since 2000.
It is unclear how much residual protection he would have had from his earlier vaccinations.
Hatfill and his lawyer, Victor M. Glasberg, described in detail their efforts to cooperate with law enforcement, saying they had been met with leaks to the press, such as a copy of a novel about bioterrorism that Hatfill had stored on his computer.
The FBI has already searched his apartment in Frederick, Md., twice, his car, a storage locker in Florida and the home of his girlfriend, they said.
Glasberg said the most recent search of his home, on Aug. 1, was conducted by surprise with a criminal search warrant, although he was working to arrange a date for another voluntary search.
Soon after agents arrived, news helicopters were hovering overhead as FBI and Postal Service agents wearing protective gloves searched his apartment complex.
"The FBI agents had promised me that the search would be quiet, private and very low key. It did not turn out that way," Hatfill said.
The law enforcement official said Sunday the FBI would never give prior notice of a search if a warrant had been obtained. "That just isn't the way we do things," the official said.
Hatfill said he has been cooperating with the investigation since the fall, when two FBI investigators asked to interview him. He said he spoke with them in a "cordial and short" session and agreed to take a polygraph test, which was being administered to others. Hatfill said he was told by the examiner that he had passed.
Soon after, Hatfill said, accusations from a reporter about his involvement in the attacks led his employer, the defense contractor Science Applications International Corp, to fire him.
Hatfill then got a job with Louisiana State University's National Center for Biomedical Research and Training. But he was suspended with pay after the Aug. 1 search of his apartment complex.
"I am appalled at the terrible acts of biological terrorism," Hatfill said. "But I am just as appalled that my experience, knowledge, dedication and service relative to defending Americans against biological warfare has been turned against me in connection with the search for the anthrax killer."