Suicide follows years of investigation into anthrax attacks

After four years pursuing one former Army scientist on a costly false trail, FBI agents probing the deadly anthrax letters of 2001 finally zeroed in last year on a different suspect: another Army scientist from the same research center at Fort Detrick in Frederick, Md.

Over the past 18 months, even as the government battled a lawsuit filed by the first scientist, Dr. Steven Hatfill, investigators built a case against the second one, Bruce Ivins, a highly respected microbiologist who'd worked for many years to design a better anthrax vaccine.

Last weekend, after learning that prosecutors were preparing to indict him on murder charges, Ivins, a 62-year-old father of two, took an overdose of Tylenol with codeine. He died in a Frederick hospital Tuesday, leaving uncertainty about whether the anthrax mystery had finally been solved.

The apparent suicide of Ivins was a dramatic turn in one of the largest criminal investigations in the nation's history. The attack, the only major act of bioterrorism on U.S. soil, came in the aftermath of the Sept. 11 attacks. It killed five people, sickened 17 others and set off a wave of panic.

In the days after the letter attacks, in September and October 2001, Ivins joined about 90 of his colleagues at the Army Medical Research Institute of Infectious Diseases in a round-the-clock push to test thousands of samples of suspect powder to see if they were anthrax. Later, in April 2002, he came under scrutiny in an Army investigation of a leak of potentially deadly anthrax spores outside a sealed-off lab at Fort Detrick. He later admitted he had discovered the leak but hadn't reported it.

A federal law enforcement official said Ivins had been regarded as a strong suspect and that agents had been nearing an arrest, and a lawyer familiar with the investigation said he believed prosecutors had planned to charge only Ivins.

A lawyer who had represented Ivins since May 2007 insisted Ivins was innocent.

“We assert his innocence in these killings and would have established that at trial,” Paul Kemp said. “The relentless pressure of accusation and innuendo takes its toll in different ways on different people, as has already been seen in this investigation.”

Kemp was referring to the case of Hatfill, who received a $4.6 million settlement from the government in June to settle a lawsuit accusing the FBI and the Justice Department of destroying his career and personal life with leaks.

Two puzzles have haunted investigators from the beginning: the motive of the perpetrator and his skills. Because the notes in some of the letters mailed to news organizations and two U.S. senators included radical Islamist rhetoric, investigators initially thought the letters might have been sent by al-Qaida. But the FBI quickly narrowed its main focus on a different profile: a disgruntled U.S. scientist who wanted to raise an alarm about bioterrorism.

The other puzzle involved the skills necessary to produce the high-quality aerosol powder contained in the letters addressed to the senators, Tom Daschle, D-S.D., and Patrick Leahy, D-Vt. Scientists said there was no evidence that Ivins, though a vaccine expert with access to dangerous forms of anthrax, had the skills to turn the pathogen into an inhalable powder.