McLEAN, Va. (AP) – A federal judge on Friday dismissed a libel lawsuit filed against The New York Times by a former Army scientist once identified as a person of interest in the 2001 anthrax attacks.

U.S. District Judge Claude Hilton in Alexandria dismissed the case a week after lawyers for the Times argued that Steven Hatfill should be considered a public figure under libel law, which makes it much more difficult for a public figure to win a judgment than a private citizen.

The judge did not explain his ruling in the order issued Friday.

Mr. Hatfill had claimed that a series of columns falsely implicated him as the culprit in the anthrax attacks.

His lawyers had argued that even if Mr. Hatfill qualified as a public figure, they could still prevail at trial because they had uncovered serious flaws in the reporting of columnist Nicholas Kristof.

Times lawyers argued that Mr. Hatfill qualifies as a public figure because he had injected himself into the national debate about bioterrorism years before the anthrax attacks. He had occasionally been quoted as an expert in the media, and even once donned a chemical suit for a magazine photo.

Times spokeswoman Catherine Mathis said the paper was pleased with the ruling. Hatfill’s lawyers could not immediately be reached for comment Friday evening.

This is the second time that Judge Hilton has tossed out Mr. Hatfill’s claim against the paper. Judge Hilton dismissed the case back in 2004 after ruling that Mr. Kristof’s columns accurately reflected the state of the FBI’s investigation, in which Attorney General John Ashcroft labeled Mr. Hatfill a “person of interest.”

But the 4th U.S. Circuit Court of Appeals in Richmond narrowly overturned Judge Hilton’s ruling in 2005, determining that a reader of Mr. Kristof’s columns could reasonably infer that Mr. Hatfill was the anthrax killer.

Mr. Kristof said all along that he never intended to accuse Hatfill but simply wanted to prod a dawdling FBI investigation. He initially referred to Hatfill in his columns only as “Mr. X,” and identified him by name only after Mr. Hatfill held a news conference to denounce rumors that had been swirling around him.

Mr. Hatfill argued that the columns contained enough information about him that people could deduce his identity.

Mr. Hatfill is also suing former Attorney General John Ashcroft, the Justice Department and others, claiming they violated his civil rights.

Five people were killed and 17 sickened by anthrax that had been mailed to lawmakers on Capitol Hill and members of the news media in New York and Florida just weeks after the Sept. 11, 2001, terrorist attacks. The case remains unsolved.