Former FBI Director James Comey conceded in his recently released memoir that when the FBI launched its investigation into Hillary Clinton’s use of a private email server the agency did not believe career prosecutors at the Justice Department would move on the case.

In the controversial book, titled A Higher Loyalty: Truth, Lies, and Leadership, Comey claims that the FBI was not “going to prejudge the result.” Yet, he immediately admits that they did just that.

Comey writes:

So although we were not going to prejudge the result, we started the Clinton investigation aware that it was unlikely to be a case that the career prosecutors at the Department of Justice would prosecute. That might change, of course, if we could find a smoking-gun email where someone in government told Secretary Clinton not to do what she was doing, or if we could prove she obstructed justice, or if she, like Petraeus, lied to us during an interview.

Comey’s justification for pre-judging the Clinton email case was to compare her to General David Petraeus, who pleaded guilty to one charge of mishandling classified information after he was accused of providing classified material to his official biographer while he served as CIA director.

Comey writes:

Despite the endless drumbeat in the conservative media, filled with exaggerated scandals and breathless revelations of little practical import, Hillary Clinton’s case, at least as far as we knew at the start, did not appear to come anywhere near General Petraeus’s in the volume and classification level of the material mishandled. Although she seemed to be using an unclassified system for some classified topics, everyone she emailed appeared to have both the appropriate clearance and a legitimate need to know the information.

Comey does not explain how the FBI could know at the start of its probe that Clinton’s case did not “come anywhere near General Petraeus’s.”

Comey made similar claims in his interview with ABC News’ chief anchor George Stephanopoulos ahead of the release of his memoir last week.

During the interview, Comey stated:

They’ll prosecute cases like David Petraeus’. But they’re very unlikely to prosecute a case unless you can show the person, like Petraeus, clearly knew they were doing something they shouldn’t do. There’s evidence of obstruction of justice or disloyalty to the United States, spy — indications. But without those, sloppiness, even extreme sloppiness, is handled through administrative discipline. Somebody is not prosecuted. And I’ve gone through 50 years of cases. I don’t know of a case where anyone has ever been prosecuted for just being careless, even extremely careless. And so when the case was open, we know that history. And so the investigators knew that, unless they found something that was a smoking gun, where someone told Secretary Clinton, “You know, you shouldn’t be doing this,” or where she acknowledged it or where somehow there’s an indication of her obstructing justice, the case was unlikely to be prosecuted.

Aaron Klein is Breitbart’s Jerusalem bureau chief and senior investigative reporter. He is a New York Times bestselling author and hosts the popular weekend talk radio program, “Aaron Klein Investigative Radio.” Follow him on Twitter @AaronKleinShow. Follow him on Facebook.

Written with research by Joshua Klein.