July 20, 2004 — FBI agents returned to search the U.S. Army's biological weapons labs at Fort Detrick, Md., as part of a last-ditch effort by the bureau to make a case in the 2001 anthrax attacks, federal officials tell ABC News. The FBI has set a self-imposed Oct. 1 deadline for its agents to build a case that will stand up in court, officials said. After matching the anthrax used in the deadly attacks with anthrax at the Army facility, investigators now hope to further narrow the hunt among the hundreds of researchers who have worked at the Fort...