-- Fears that al Qaeda had some role in the anthrax letter attacks that killed five and terrorized the U.S. 10 years ago surfaced early in the investigation.
"THIS IS NEXT. TAKE PENACILIN NOW. DEATH TO AMERICA. DEATH TO ISRAEL. ALLAH IS GREAT," read the anthrax-laden letter sent to NBC newsman Tom Brokaw on Sept 18, 2001, at the start of the attacks. At least five letters were sent in the attacks that autumn, all containing similar words.
Those messages likely contributed to one of the more curious endeavors of the nine-year "Amerithrax" investigation into the anthrax murders, the retrieval of a suspected terrorist lab, right down to the pipes of the kitchen sink.
The National Research Council in February delivered an evaluation of the science used by investigators to tie the anthrax used in the attacks, a mutant-laced variant of the "Ames" anthrax strain, to the infamous RMR-1029 flask at the United States Army Medical Research Institute (USAMRIID) at Fort Detrick, Md. The flask was controlled by a researcher named Bruce Ivins, who committed suicide in 2008, days before investigators say they had intended to indict him for the crime. Based in part on the link to the RMR-1029 flask, the FBI, in its investigative summary of the case, concluded, "Ivins, alone, mailed the anthrax letters." The conclusion, though, is still disputed by some observers. Even the NRC said it was "not possible to reach a definitive conclusion about the origins of the anthrax," in its evaluation.
In May of 2004, U.S. investigators weren't so sure either. They had information about al Qaeda plans to develop an anthrax program, the NRC report said. So FBI investigators and "partners from the intelligence community" then visited a suspected bioterror lab abandoned by al Qaeda and collected swabs there. Three samples tested positive for Ames strain anthrax in tests, conducted at the USAMRIID lab. They had been taken from "an unopened medicine dropper package, a sink, and a sink drain hose," according to a partly-declassified FBI report.
Subsequent tests at microbiologist Paul Keim's lab at Northern Arizona University found signs of the Ames strain of anthrax on two of the three samples, according to the same report. "As a result of these findings, a third collection mission was conducted in November 2004 and this time large portions of the site were returned intact to the United States, including the entire sink, drain, and associated plumbing," said the NRC report. The retrieved lab was "extensively sampled" for both living anthrax and anthrax DNA.
So, what did they find? According to the NRC report, "all the tests were negative" for anthrax. Further tests of samples conducted in 2007 also showed no signs of anthrax. (The first ones likely had produced false positive results, a hazard of tests primed to turn up any traces of a pathogen.)
"While it is undoubtedly true that al Qaeda was seeking to establish an offensive bioweapons program in 2001 , Task Force agents were unable to find any link between al Qaeda and the letter attacks in the United States, or even that, at the time of the attacks, any al Qaeda operatives had access to the type and quality of anthrax pathogen used in the 2001 attacks," says the FBI's investigative summary of the case.
The NRC panel, headed by Lehigh University president Alice Gast, however, "consider these data to be inconclusive regarding the possible presence of B. anthracis Ames at this undisclosed overseas site," according to their report. Echoing findings elsewhere in the report the panel complained that investigators needed to take additional steps to validate the anthrax tests used in the investigation and to understand the naturally-occurring level of anthrax in places such as Afghanistan. The differences exposed the chasm between the level of certainty required by scientists, who want very strong statistical reassurance, and those of crime investigators, who seek a weight of evidence necessary to convince a jury of murder and no more.
So, those who still voice doubts about the investigation, such as Rep. Rush Holt, D. - N.J., can point to the al Qaeda threat as a still unsettled alternative to the anthrax attacks. Scientists would like to see more basic research done on anthrax in case of another attack.
"If anthrax pops up again, we still don't know enough about what type of strains are in the environment," says former FBI investigator Bruce Budowle of the University of North Texas Health Science Center at Fort Worth. In microbial forensics investigations, scientists are looking for assurances that results could be incorrect only 1 in 100 times, he says. But to reach that would be "almost a physical impossibility," he adds, given that microbe characteristics can shift markedly over small distances.
Another point made in the NRC report is that more research could be done on the evolution of anthrax, to verify how the mutations that marked anthrax in the RMR-1029 flask developed. "I have a model of how they evolved and it explains what happened very well," Keim says now. "But it is critical we understand the evolution of how these morphs (mutants) arise," he says.
"If terrorists released Bacillus anthracis over a large city, hundreds of thousands of people could be at risk of the deadly disease anthrax," reads the summary of an Institute of Medicine report released only Friday. Even after a decade, "many public health authorities and policy experts fear that the nation's current systems and plans are insufficient to respond to the most challenging scenarios, such as a very large-scale anthrax attack."