FBI Director to Herridge: 'We Do Investigations, Not Security Inquiries'

Judge Nap: Why the FBI Could Prove Hillary Violated Espionage Laws

There's a new development this morning in the Hillary Clinton email scandal.

The Washington Post reported that a longtime top aide to Mrs. Clinton, Cheryl Mills, walked out on her interview with the FBI, which is investigating the private server used by Clinton while she was secretary of state.

An investigator had apparently broached a topic that Mills and her attorney thought was going to be off-limits.

Mills then reportedly returned, but left repeatedly to confer with her lawyer.

Fox News senior judicial analyst Andrew Napolitano explained the particulars this morning, saying that the meeting between Mills and investigators was voluntary.

Napolitano said that usually before these interviews, attorneys can negotiate on what topics will be discussed.

He said it appears that the FBI agreed not to ask about emails, since Clinton's legal team argued that Mills was Clinton's attorney at the time so their communications were protected by attorney-client privilege.

Napolitano said the FBI wouldn't have pushed the envelope on the issue unless it already knew the answer from gathering evidence.

The judge said Mills' walk-out is newsworthy, but doesn't have much of an impact on Clinton's legal situation.

"It does tell you this: the FBI is willing to leak when things don't go its way."

Watch Judge Nap's analysis above from "Varney & Co."

Survey: Troops Prefer Trump to Hillary by a Huge Margin

'Criminal Referral Would Be Difficult for Hillary to Overcome'

There's Now a Dating Site for Fleeing Anti-Trumpers to Meet Canadians

Meantime, Peter Schweizer, author of "Clinton Cash," discussed the new developments on America's Newsroom this morning.

He said that the investigators wanted to get answers from Mills on why the private server was created.

Schweizer explained that the Clinton team is claiming that Mills did not have to answer because of "attorney-client privilege"

"She was the chief of staff at the State Department at the time. She was certainly not their private, personal attorney so I don't quite understand the argument," he noted.

Schweizer said he believes it will be very difficult to prove that Clinton intentionally wanted to avoid scrutiny of her emails.

But he said that the investigation into the Clinton Foundation is "far more troubling" for the Democratic presidential frontrunner.