BOB GARFIELD: This week, the New York Times and its columnist Nicholas Kristof were slapped with lawsuits by government scientist Steven J. Hatfill. In 2002, Hatfill was named a, quote, "person of interest" in the anthrax attacks that terrorized the nation and killed five people. No one was ever charged, but Hatfill was the focus of several of Kristof's columns. Identified as "Mr. Z," a bio-terrorism expert whose activities were suspicious, to say the least, Hatfill's suit charges Pulitzer Prize-winning Kristof with defamation. It's likely that much of the information cited in Kristof's columns was leaked by investigators on the case. When Hatfill first aired his complaints in August of 2002, Brooke looked at how law enforcement uses the media to send up trial balloons.

BROOKE GLADSTONE: We've seen this sort of thing before -- a presumption of guilt before the facts are in; what appears to be the sweating of suspects by law enforcement through anonymous leaks in the press. There are the notorious examples of presumed Atlanta bomber Richard Jewell and presumed spy Wen Ho Lee. Now there's presumed anthrax attacker Steven Hatfill. Nick Kristof is a columnist for the New York Times.

NICK KRISTOF: You know, if you look back at how the media's handled various cases, then we really have, at times, ruined the lives of people by tossing their names out there before they've been subject to any kind of criminal process, and when our presumption has to be that they're innocent and just caught in this incredible nightmare.

BROOKE GLADSTONE: Yet over the past few months, Kristof has assiduously compiled and reported an impressive but entirely circumstantial case against the man he called "Mr. Z." His unique access to the precise kind of anthrax used in the attacks that killed five people, his poor showing on three polygraph tests. He reported "Z's" own claim to have taken part in the actions of the White Army in Rhodesia where there is evidence that, in the late '70s, anthrax was released and sickened 10,000 blacks. But Kristof never used Steven Hatfill's name, and he says his intention never was to convict "Mr. Z."

NICK KRISTOF: It was to light a fire under the FBI. I think the FBI did a catastrophic job for months and months and months. I think they weren't prepared to deal with a high tech scientific investigation like this; it took 'em months to catch up.

BROOKE GLADSTONE: And to keep it hot for the FBI, Kristof piled on the circumstantial fuel -- "Z's" foreign trips; his alias and stray remarks that have since been rebutted in other newspapers. Kristof's impatience was fed by experts in the community of bio-terror and within the FBI itself, but he always stopped short of naming "Mr. Z," even after others did, until Hatfill himself came forward.

NICK KRISTOF: It's a very awkward position. This is a crucial public policy issue and a fundamental matter of avoiding terrorism in the future as well, and so we have to investigate, we have to report it, and yet we don't want to make the mistakes that we did in the past.

BROOKE GLADSTONE: The mistakes cited by Hatfill's lawyer was the media frenzy over Richard Jewell, an innocent man who became a prime suspect in an Atlanta bombing during the 1996 Olympic Games. Suspicion fell on Jewell early in the investigation, but as in Hatfill's case, there was no physical evidence, and so anonymous officials in law enforcement -- perhaps the police - perhaps the FBI or both -- fed the press with hints and suppositions. When Richard Jewell was invoked in Hatfill's case, many in the media declared that he was being railroaded in the very same way, but reporters on this case did not rush what they were learning into print. Though they knew his name, they held back for months.

DAN KLAIDMAN: I don't think there's a serious journalist in America covering these issues who was not thinking about the Richard Jewell case and about the Wen Ho Lee case as they were reporting on the anthrax investigations.

BROOKE GLADSTONE: Newsweek's Dan Klaidman reported on Richard Jewell and Wen Ho Lee and now Steven Hatfill. In fact, he reported what appears to be a leak that could only have come from the FBI. Trained dogs were exposed to odors derived from the anthrax letters. Then they were exposed to various people and places. The dogs reacted to Hatfill's apartment, his girlfriend's apartment and restaurants he'd recently patronized -- but to no other people or places. Nick Kristof.

NICK KRISTOF: That, I understand, was very closely held within the FBI by only a very small number of people and was reported within about two or three days of the FBI itself knowing that.

DAN KLAIDMAN: They thought "Aha! We have a breakthrough," but then realized, "Well -- but we don't have any physical evidence tying him to the crime."

BROOKE GLADSTONE: Klaidman says FBI leaks are very rare, and so does Ronald Kessler, a former reporter for the Wall Street Journal and the Washington Post who writes extensively on the FBI. But, he notes, the FBI will make use of the media to sweat out a suspect. For instance, when an anniversary of an unsolved murder approaches, the bureau may prod the press for a follow-up, because it may spur the killer to visit the grave site.

RONALD KESSLER: FBI agents are there, videotaping, and they actually have caught the suspects in these cases. That shows how the press can be used to try to solve crimes.

BROOKE GLADSTONE: In Hatfill's case, Kessler suggests the leaks are similarly strategic.

RONALD KESSLER: The purpose of these leaks is to try to shake up the suspect and see what he'll do and see if more evidence can be obtained that way. It's almost unheard of for FBI investigations to be leaked, we know, with some exceptions, and the fact that this is happening I think indicates that there is this motive involved.

BROOKE GLADSTONE: Reporters often say that the motives of leakers are irrelevant if the information checks out, and in this case, New York Times columnist Nick Kristof contends the need is great and that Hatfill's story has not played out, like Richard Jewell's. But he also says he's guided by a story he watched unfold as a reporter in Japan when a Mr. Kono was falsely accused of releasing sarin nerve gas in Matsumoto.

NICK KRISTOF: It was just an epic tragedy. His wife was comatose in this attack. I was wondering, you know, how the U.S. press would have handled it, and I thought that in fact we would have done even worse for Mr. Kono, because the Japanese press, for the most part, did not name him. In the U.S., we would have. We would have written about where his kids were.

BROOKE GLADSTONE: But, he adds, if the Japanese press had been less deferential in its treatment of a suspicious cult called Aum Shinri Kyo perhaps that gas attack and the one that followed in the Tokyo subway never would have happened.

NICK KRISTOF: In the U.S., we would have been much harder on Kono, but we also would have been much, much harder and tougher on Aum Shinri Kyo. We would have had people pretend to join the cult and write about it, and I think, very likely, the result would have been that the cult would have been closed down before it ever had a chance to spread the gas in the subway attacks. And so, you know, it's a two-edged sword. It's an enormously sensitive problem. It's a headache for all of us. But I don't think the answer is always just to pull back completely and not to investigate. I think that's a mistake.

BROOKE GLADSTONE: Since Hatfill issued his heartfelt defense before the cameras, the pendulum has swung in favor of Hatfill as victim. As the case develops, inevitably the public will make its judgments and unmake them, in turn. But if there were no pendulum, would we really be better off? Nick Kristof helped to energize what some call "aggressive investigation," others a "witch hunt" with his portraits of the suspicious "Mr. Z." Perhaps the best any reporter can do is consider the facts and stick to the "Z" until the "Z" comes forward.