Dr. Kenneth Berry was sounding alarms about bioterrorism well before the 2001 anthrax mailings that killed five people, and he advocated gas masks for Americans at a 2001 EPA-sponsored conference.

He called for anthrax vaccines (search) in 1997, the year the emergency room doctor proposed a training program for 200,000 first responders, and he won a patent in March on a tracking device for biological, chemical and nuclear attacks.

"The 21st century is going to be a different place," he said at a terrorism forum in 1997, according to a transcript.

In recent days agents have searched Berry's home and former apartment in Wellsville, his parents' summer home on the Jersey shore and a car Berry reportedly kept at an airport in rural southwestern Pennsylvania, where some of his relatives live. An FBI spokesman said the searches were part of the bureau's investigation of the unsolved 2001 anthrax attacks.

Berry told police that he had nothing to do with anthrax, Point Pleasant Beach, N.J., police Chief Daniel DePolo said in a news conference Friday.

The FBI said the public was not in immediate danger, but would not say what agents were seeking.

The searches came nearly three years after five people were killed and 17 fell ill when anthrax-laced envelopes were mailed to government offices and news media, triggering even more fear in a country already shaken by Sept. 11. The attacks have baffled government investigators, who have turned up few leads.

During the winter, a couple of agents asked about Berry in the small village of Wellsville (search), where he lives with his wife and children, said resident Gary Barnes.

The FBI presence seemed odd in the town of 5,000 residents near the Pennsylvania line, better known for its annual hot-air balloon rally and trout derby in the Allegany foothills.

Barnes, manager of the Wellsville Municipal Airport where Berry kept his small plane, said the agents wanted to know the doctor's flight routes and were told he mainly flew back and forth to Pittsburgh for his job as an emergency room doctor there.

"We had no knowledge of what it was leading to," Barnes said of the questioning.

Berry works at the University of Pittsburgh Medical Center-McKeesport (search), hospital officials told Pittsburgh newspapers. They would not elaborate.

Wellsville Mayor Brad Thompson said agents spent 14 hours inside Berry's home Thursday.

Barnes said he found Berry to be a friendly person and a good pilot, and unusual only in that he flew his plane to work every week.

"He's a little bit different type of person but I just can't believe he'd be involved in something as bad as what it potentially could be," Barnes said.

While agents were combing through his home, Berry was arrested in Point Pleasant Beach, N.J., on domestic charges unrelated to the anthrax investigation. Authorities said he had been fighting with four family members at a motel, and the family members required medical treatment. He was released on $10,000 bail.

Attempts to reach Berry, 46, by telephone and e-mail have been unsuccessful.

"I truly don't believe it," said Pat O'Shea, who lives near Berry's parents' lagoon-front bungalow in Dover Township, N.J. "I know he's a bioterrorism expert. He's a brilliant man."

Berry received his medical degree from the American University of the Caribbean, School of Medicine, in 1983. He was on the staff at Jones Memorial Hospital in Wellsville from December 1996 until he resigned in October 2001, hospital spokeswoman Judy Burt said. He is a past president of the American Academy of Emergency Physicians.

Berry pleaded guilty in 1999 to disorderly conduct to settle charges related to the fake will of a deceased former colleague. Authorities said Berry and a second colleague were listed as witnesses to the will, which had been written by the late doctor's wife. Berry was initially charged with two counts of forgery but pleaded to a lesser violation that allowed him to keep his medical license.

William DiBerardino, retired administrator of Jones Memorial Hospital, said he doesn't believe Berry would do anything to hurt his country.

"He's just a very bright guy," DiBerardino said. "He is a little different in what he does and the way he is, but not in any bad sense."