Scientists and legal experts questioned the reliability of novel genetic tests that the FBI says link anthrax letters to an Army bioweapons scientist.
Because the FBI has never offered such tests in criminal cases, it’s uncertain that the results would have been admitted in court as evidence against Bruce E. Ivins, who committed suicide last week, experts said.
“Microbial forensics is still a nascent field, and, as far as I know, no one has ever been convicted in a U.S. court on the basis of microbial forensic evidence,” said Peter Hotez, a microbiologist at George Washington University. “It’s untested. In all likelihood, he’s the guy, but you can’t say it’s beyond a reasonable doubt.”
Key piece of evidence
Gene sequencing that linked the highly refined anthrax spores used in the anthrax letters to a flask in Ivins’ laboratory was a key piece of evidence cited by the Justice Department Wednesday as proof Ivins acted alone.
The government said it will close the case soon. Before he died, Ivins, a researcher at the Army’s bioweapons lab at Fort Detrick, Md., told people he expected to be charged with the five anthrax killings, court papers said.
The uncertainty about whether a trial judge would admit the results into evidence may explain why the FBI didn’t move faster to arrest Ivins after learning he had been hospitalized for exhibiting homicidal and suicidal tendencies, said one former federal prosecutor.
“They never arrested him because they wanted him to confess,” said Joseph diGenova, a former U.S. attorney for the District of Columbia. He said the FBI used a tactic designed to pressure a suspect into confessing because prosecutors knew the scientific analysis would have such problems.
Ivins died July 29 after taking an overdose of Tylenol.
In a court document released Thursday, investigators said they seized a bulletproof vest, homemade body armor and ammunition during a July 12 search of his house, office and cars.
Warrant signed
A federal judge Thursday signed a warrant authorizing FBI agents to search computer terminals at a Frederick, Md., public library that Ivins was seen using while under surveillance. The FBI said it was seeking “any indication” of “writings identifying a plan to kill witnesses or names of intended victims” or “suicide letters.”
Some experts said it’s premature to close the book on the case and that investigators should share more evidence with the scientific community.
“I heard first a solid claim from the FBI that they are absolutely sure the genetic analysis pinpointed it, and then later on I heard some weasel wording that made it a little less crystal clear,” said Philip K. Russell, a biodefense expert who directed emergency preparedness for the U.S. Department of Health and Human Services after the attacks.
Ivins’s lawyer, Paul F. Kemp, said the government never showed him the laboratory reports that officials said link the letters to the anthrax handled by his client. “If they’re so proud of these reports, why didn’t they release those yesterday?” Kemp said.
