A review of the Federal Bureau of Investigations scientific work on the investigation of the anthrax letters of 2001 concludes that the bureau overstated the strength of genetic analysis linking the mailed anthrax to a supply kept by Bruce E. Ivins, the Army microbiologist whom the investigators blamed for the attacks. The review, by a panel convened by the National Academy of Sciences, says the genetic analysis did not definitively demonstrate that the mailed anthrax spores were grown from a sample taken from Dr. Ivinss laboratory at Fort Detrick in Frederick, Md. The academys report faults the F.B.I. as failing to take advantage of scientific methods developed between the mailings in 2001 and its conclusion after Dr. Ivinss suicide in 2008 that he was the sole perpetrator. The academy panel, which was paid $1.1 million by the F.B.I. for its review, assessed only the scientific aspects of the investigation and not the traditional detective work. Representative Rush D. Holt, a New Jersey Democrat and physicist who has followed the case, said he thought the academys review showed that the F.B.I. attached too much certainty to the scientific parts of the case. I also think it shows the case was closed prematurely, Mr. Holt said. He said he was reintroducing a bill to create a national commission, similar to the Sept. 11 panel, to take a more comprehensive look at the anthrax case and its implications.