According to former Justice Department officials familiar with the case at least a dozen of those people still have not been eliminated as "persons of interest." And yet, only Hatfill was ever identified.
Hatfill wouldn't give 60 Minutes an interview; but his lawyer, Tom Connolly, did speak to Stahl.
"If you want a blueprint for ruining somebody, this is how you do it. You engage in a campaign of leaking investigative information to your favorite reporters who then write it, and create a caricature of you," Connolly tells Stahl.
Asked if he knows for sure that it was the FBI and Justice Department that were doing the leaking, Connolly says, "I know as a matter of existential truth it was the FBI and DOJ."
How does he know it?
"Because I have FBI agents under oath, who acknowledge under oath, that it couldn't have been coming from anywhere else because of what was being leaked," he explains.
Nine reporters also gave sworn testimony. In their stories, they often identified their sources as law enforcement officials. Some of the reports would make anyone suspicious.
"I can remember reading articles about your client and thinking: 'Oh this is pretty devastating stuff,'" Stahl remarks. "That he had worked at a U.S. Army laboratory in Maryland and had access to anthrax."
"Let me say one thing with absolute certainty: he has never in his life ever worked with anthrax," Hatfill's attorney, Tom Connolly, insists.
Asked if there was anthrax at the lab, Connolly tells Stahl, "It was in a variety of a wet slurry, not a dry powder."
Asked to explain, Connolly says wet slurry is a paste, while the substance in the envelopes was a dry powder.
"To convert a wet slurry to a dry powder, meaning to weaponize it, is a feat of amazing engineering which requires sophisticated equipment. And it would leave telltale signs behind. Now let me just say one of other thing. The head of Fort Detrick, where this alleged slurry was, has testified under oath that there is no evidence whatsoever that any of that anthrax has been missing or was it ever missing," Connolly says.
"Something else that came out that Dr. Hatfill went on Cipro right before these anthrax letters started appearing. Cipro is what you're supposed to take if you get anthrax, if you're exposed to it," Stahl remarks.
"Before the attacks he had surgery. So yes, he's on Cipro. But the fuller truth is in fact he was on Cipro because a doctor gave it to him after sinus surgery," Connolly explains.
On the Cipro question, Hatfill's medical records confirm that five weeks before the anthrax attacks, he had sinus surgery and was prescribed Cipro.
Connolly thinks the most damaging leak of all involved evidence-sniffing dogs, which he calls "the magic bloodhounds."
According to Newsweek magazine, the FBI used three purebred bloodhounds, Lucy, Knight and Tinkerbell, who "went crazy" at Hatfill's apartment.
"The criticism I have with these magic bloodhounds is they have been responsible for a number of false arrests," Connolly argues.
Including the arrest of a man on charges of multiple rapes in California, based largely on Tinkerbell and Knight's purported power of smell. But he was ultimately cleared by DNA evidence. And now 60 Minutes has learned in the anthrax case that the dogs also alerted to another scientist who worked at the same Army lab as Hatfill.