In the months before the anthrax attacks of 2001, Dr. Steven J. Hatfill helped design and set up mock bioweapons laboratories for U.S. agencies to train commandos and intelligence officers to recognize germ factories in Afghanistan, Iraq or elsewhere.
The work won him a government commendation. But it may also have given the FBI a reason to spend thousands of man-hours scrutinizing every detail of Hatfill's life, searching for a link to the anthrax-laced letters that killed five people.
For training sessions he led in West Virginia, Hatfill provided an anthrax simulant called Bacillus globigii, defense officials say. The nontoxic relative of the deadly anthrax bacteria was sprinkled around so that trainees could use high-tech equipment to detect the germs.
For labs set up on the Pacific island of Guam, at a base in the Western United States and at the Special Forces training facility at Fort Bragg, N.C., Hatfill scavenged discarded biological equipment of the kind used to turn germs into weapons.
But the units never manufactured any germs and were not capable of making the anthrax mailed in the attacks, according to defense officials and contractors involved in the projects.
"No way in the wildest dream could it have been used to make anything," says William C. Patrick III, a Frederick scientist retired from Fort Detrick who worked closely with Hatfill on one project.
Neither have investigators found a single spore of anthrax on the equipment or among Hatfill's belongings, law enforcement officials say.
So, the critical question about Hatfill's work on mock bioterror labs remains unanswered: Does it have any relevance to the deadly letters that drove U.S. senators and Supreme Court justices out of their offices and gave the nation a taste of the devastation a bioattack could cause?
Or does it merely help explain why one of the biggest criminal investigations in history has focused so closely on one man while failing to crack the case?
Over the past 18 months, FBI surveillance squads have pursued Hatfill in convoys whenever he leaves home. Investigators imported bloodhounds from California in an effort to link Hatfill to a scent found on the letters - a technique some bloodhound experts say is so flawed that it is meaningless.
Agents have repeatedly searched the Frederick apartment where Hatfill lived until August and his girlfriend's Washington apartment, where he lives now. Most recently, they spent $250,000 to drain a pond in the woods near Frederick, sifting the muck and pumping dirty water into a tanker truck to be tested for anthrax.
But the evidence turned up by the Amerithrax task force, as the investigation is known, has been insufficient either to charge Hatfill with the crime or to clear him so that get on with his life.
After a front-page article in yesterday's New York Times detailed Hatfill's role in building one of the training labs, the scientist again denied any connection to the attacks.
"Steve Hatfill knows nothing about the anthrax attacks," said his spokesman, Pat Clawson. "He is a loyal American patriot who loves his country. ... His dedication to duty has often required great personal risk and sacrifice.
"For legal and security reasons, he is unable to speak publicly about his work. If the facts were known, we believe most Americans would be grateful for his service to our nation. He looks forward to the day when his name is cleared and his reputation restored so he can resume his career of public service."
Most of Hatfill's training work was conducted for Science Application International Corp., a defense contractor that employed him from 1999 until March 2002. According to those familiar with his work, FBI agents infiltrated some of his classes to size him up as a potential suspect after the anthrax mailings.
Agents spent two weeks studying a mock mobile biolab he helped build on an old truck chassis on the property of a Frederick contractor, AFW Fabrication, then halted the unit for another look while it was being transported to Fort Bragg, according to a source close to the case.
Even as he came under FBI suspicion, the Defense Intelligence Agency and the U.S. Special Forces Command allowed Hatfill to continue working on SAIC's contracts. At the same time, he was completing training as a United Nations biological weapons inspector, though he never was deployed to Iraq.
Even as the FBI was grilling him in May 2002, the Defense Intelligence Agency sent him a commendation, and officials there still have a high opinion of his work.
"Everyone says this is a smart guy - extremely helpful," said one agency official. "They say they learned a hell of a lot from him."
But media scrutiny has uncovered an erratic and deceptive side to Hatfill's personality, reflected in falsehoods and exaggerations on his resume.