If this were one of Trey Gowdy’s murder prosecutions, it would be declared a mistrial.

For 17 months, the ex-prosecutor who leads the House Benghazi committee has labored to give the appearance of diligence and impartiality. But, in an inexplicable outbreak of honesty in recent weeks, the thing is unraveling just in time for Gowdy’s moment in the spotlight: Hillary Clinton’s testimony Thursday.

First came House Majority Leader Kevin McCarthy’s implication that the committee was empaneled for the purpose of hurting Clinton’s poll numbers.

Then Rep. Richard Hanna, R-N.Y., voiced his view that “there was a big part of this investigation that was designed to go after people and an individual, Hillary Clinton.”

This was followed by Bradley Podliska, an Air Force Reserve intelligence officer and a self-described conservative, who was fired as a Republican committee staffer – in part, he said, because he resisted pressure to focus on Clinton. Podliska called it “a partisan investigation” with a “hyper-focus on Hillary Clinton.” He said the “victims’ families are not going to get the truth.”

Gowdy is most displeased. “I have told my own Republican colleagues and friends: Shut up talking about things that you don’t know anything about,” he said on CBS’ “Face the Nation” on Sunday. “And unless you’re on the committee, you have no idea what we’ve done.”

But it appears some on the committee, over $4.5 million into the probe, have no idea what they’re doing, either. Various Keystone-Cops moments performed by the panel have Gowdy looking less like Jack McCoy and more like Jacques Clouseau as he goes after the likely Democratic presidential nominee.

Gowdy this month alleged that one of the emails on Clinton’s private server contained the name of a CIA source, “some of the most protected information in our intelligence community.”

But the CIA said the name to which Gowdy referred was not classified. The State Department asked that the name be redacted, not for security reasons but for the individual’s privacy. Gowdy, completing the comedy of errors, then released the email publicly Sunday with the person’s name, apparently unaware that the State Department had failed to redact it.

As that mess was being cleaned up, Gowdy was dealing with another. Gowdy has spoken piously about keeping his investigation above politics and about refusing to raise money from it. But my Washington Post colleague Mike DeBonis reported that Gowdy’s campaign had returned three donations after the Post inquired about the money’s ties to a political action committee that ran an incendiary ad during last week’s Democratic presidential debate.

Three $2,000 contributions had been made to Gowdy by groups affiliated with the treasurer of Stop Hillary PAC. Stop Hillary PAC had spent $10,000 on robocalls last month to boost Gowdy in his district, and its treasurer had been involved with Gowdy’s former leadership PAC.

The ham-handed targeting of Clinton predates the Gowdy panel. Rep. Darrell Issa, R-Calif., who led an earlier Benghazi investigation, suggested, falsely, that Clinton had issued a “stand-down” order to block a military response the night of the Benghazi attack. Issa also alleged, falsely, that Clinton personally authorized security reductions in Libya with her “signature” on a cable.

The contretemps have continued under Gowdy. The chairman claimed that he had “zero interest” in the Clinton Foundation and hadn’t issued a subpoena related to it or interviewed a “single person” about it other than the staffer who set up Clinton’s private email server. But Gowdy had armed marshals serve a subpoena at the home of Clinton adviser Sidney Blumenthal, and Gowdy and others asked Blumenthal many questions about the foundation.

Could such a skilled prosecutor and his experienced staff really be so hapless? Or are the mistakes more purposeful? Consider the damaging New York Times story this summer that initially reported, incorrectly, that federal inspectors general had requested a “criminal investigation” into whether Clinton “mishandled sensitive government information.”

The “senior government officials” responsible for the two false allegations were anonymous. But there are some likely suspects.

Dana Milbank is a columnist for The Washington Post. He can be contacted at:

danamilbank@washpost.com