A judge authorized the Federal Bureau of Investigation to search two public library computers that were used last month by Bruce Ivins, the alleged long-sought anthrax killer.

The government scientist, who is blamed for the 2001 anthrax attacks, committed suicide via a fatal dose of Tylenol mixed with codeine, three days after visiting the library. Therefore, investigators in this case expect to find a suicide letter, writings laying out murder schemes or other object or information that might be useful for understanding the anthrax killings, said the Justice Department’s search warrant affidavit.

The official declaration said that, on the evening of July 24, microbiologist Ivins used two computers at the library so as to visit a Web site on the subject of the anthrax investigation, as well as to examine e-mail accounts.  

Officials from the C. Burr Artz Public Library, which is located in close proximity to Ivins’s home in Frederick, voluntarily gave the computers to the authorities. According to The Justice Department, it needed a search warrant in order to examine the computers’ contents. Subsequently, two warrants were approved Thursday by Chief Judge Royce C. Lamberth of Federal District Court for the District of Columbia.

After seven years of investigation the anthrax attacks, the FBI and the Justice Department say they close the case. But some seem to be discontented. On Thursday, Congress members said the federal agents were on the wrong track, unjustly blaming a guiltless top government scientist.