WASHINGTON - There's at least one veteran of the U.S. federal Justice Department professing to be flabbergasted by news Hillary Clinton will likely avoid criminal charges over her unorthodox email practices.

He happens to be a well-known political rival.

Rudolph Giuliani expressed bafflement on different cable-news channels Tuesday after an announcement from the FBI that it wouldn't recommend charges against the presidential front-runner.

"I'm shocked," the former Republican mayor of New York, prosecutor and assistant U.S. attorney general told MSNBC.

"If I were a U.S. attorney (this case) would be indicted... A lot of reasonable prosecutors would bring this case. In fact, I think it would be unreasonable not to bring this case.... The penalty is 10 years in jail — we're talking about a felony."

Giuliani said he respects his former colleague and fellow registered Republican James Comey — the FBI director who made the announcement. But he called it inexplicable that the FBI boss decided not to recommend charges on the rationale that no prosecutor would take the case.

Comey did say it's possible laws were broken in Clinton's handling of classified material. He said it's possible foreign governments got access to Clinton's correspondence when she was secretary of state because of her weakly protected homemade email system. He also said that under similar circumstances other people might face charges.

But Comey said prosecution in such cases would usually hinge on proving wilful intent to mishandle documents or harm the national interest — and he said he'd concluded that prosecutors wouldn't go there.

Giuliani said that explanation makes no sense.

According to 18 U.S. Code 793 (f), the law carries a maximum 10-year prison sentence for someone who: "entrusted with or having lawful possession or control of any document... through gross negligence permits the same to be removed from its proper place of custody."

Giuliani said there's no reference in the law to wilful intent — just to gross negligence. And he pointed out that the FBI director specifically said Tuesday that the former secretary of state's email setup was extremely careless — which, Giuliani said, meets the textbook legal definition of gross negligence.

Yet one national security lawyer says it's not so cut and dried.

First of all, Mark Zaid said, the situation involving a secretary of state setting up her own email server is unprecedented.

"This is a tough one as it's very fact specific. I know of no cases just like this," Zaid said.

"I definitely have had clients prosecuted for mishandling classified information — such as having it at home — but that usually happens when it is clearly marked classified and there is a lot of it.

"What I can say is that I have never seen a case of this magnitude where the individual was not significantly disciplined and/or faced loss of their security clearance. I have had many clients who did far less than what transpired here and that was the result."

Several commentators including the FBI director agreed Clinton's behaviour would be the type that gets a lower-level employee stripped of their security clearance. Such clearance requirements do not apply to the presidency.

Another commentator said authorities might simply have concluded they'd lose the case in court.

Elizabeth Goitein, the co-director of the Brennan Center's Liberty and National Security Project, told the Washington Post that investigators might personally have felt that negligence occurred but concluded they couldn't prove the crime.

"Comey didn't think the evidence would support a criminal prosecution," Goitein told The Post. "That's what prosecutors base their decisions on — what the evidence shows, not what they personally think happened."

News from © The Canadian Press, 2016