Anthrax Dryer a Key To Probe
Tuesday, August 5, 2008
Bruce E. Ivins, the government's leading suspect in the 2001 anthrax killings, borrowed from a bioweapons lab that fall freeze-drying equipment that allows scientists to quickly convert wet germ cultures into dry spores, according to sources briefed on the case.
Ivins's possession of the drying device, known as a lyopholizer, could help investigators explain how he might have been able to send letters containing deadly anthrax spores to U.S. senators and news organizations.
The device was not commonly used by researchers at the Army's sprawling biodefense complex at Fort Detrick, Md., where Ivins worked as a scientist, employees at the base said. Instead, sources said, Ivins had to go through a formal process to check out the lyopholizer, creating a record on which authorities are now relying. He did at least one project for the Defense Advanced Research Projects Agency that would have given him reason to use the drying equipment, according to a former colleague in his lab.
Ivins committed suicide last week. As authorities in Washington debated yesterday how to close the long investigation of him -- a step that would signal they think no one else is culpable in the anthrax attacks -- more details began to emerge about the nature of the case they developed against him.
In recent months, investigators have collected circumstantial building blocks in an effort to establish Ivins's alleged role in the attacks, which traumatized the nation and prompted stringent mail-handling policies. Letters containing the anthrax spores killed five people, including two D.C. area postal workers, and sickened 17 others.
Scientific analysis helped researchers pinpoint the U.S. Army Medical Research Institute of Infectious Diseases as the likely source of the powder, which was the Ames strain of anthrax bacteria used in various projects at Fort Detrick. Further testing allowed them to narrow down the age of the substance, concluding that it had been cultivated no more than two years before the attacks.
Eventually, through more elaborate DNA testing of the power and tissue cultures from the victims, they determined that the powder probably came from supplies made by Ivins, to which about 10 other people had access. Authorities last week cited "new and sophisticated scientific tools" that helped advance the investigation.
Ivins was not charged before his death July 29. Paul F. Kemp, his attorney, has repeatedly asserted Ivins's innocence, and colleagues and friends say government officials fixed on the wrong man in a race to close a seven-year investigation rife with dead ends and missteps. They also note that other U.S. scientists had access to some of the same material and equipment that authorities apparently used to focus on Ivins.
The lyopholizer Ivins used in the fall of 2001 is commonly employed by pharmaceutical companies and laboratories, as well as food processors, to freeze a liquid broth of bacteria and quickly transform it into a dry solid without a thawing stage.
Scientists and biodefense experts familiar with USAMRIID's procedures say that Ivins's department rarely used such freeze-dryers, because the researchers there worked with anthrax bacteria in a liquid form.
"Dry anthrax is much harder to work with," said one scientist familiar with Ivins's lab. A lyopholizer would fit inside the ventilated "biosafety cabinet" at the lab and could have been used without drawing notice, the scientist said. The machine could have processed a few small batches of anthrax liquid in less than a day, he said.
Other biodefense experts noted that the drying step could have been carried out with equipment no more complicated than a kitchen oven. "It is the simplest . . . but it is the least reproducible," said Sergei Popov, a former Soviet bioweapons scientist who now specializes in biodefense at George Mason University. "If you go too fast you get 'sand,' " he said, referring to the coarser anthrax powder used in the first attacks, in September 2001.