FBI investigated former sheriff and Trump ally David Clarke for federal crime

Sheriff allegedly had fellow passenger detainer for shaking his head

The FBI looked into allegations against former Milwaukee Sheriff David Clarke (Scott Olson/Getty Images)

The FBI investigated former Milwaukee sheriff and Trump ally David Clarke over allegedly directing deputies to harass a plane passenger, according to court files.

The documents reveal that an FBI agent sought a search warrant to uncover more evidence about a 2017 incident involving Mr Clarke and a fellow traveller.

A man named Dan Black sued Mr Clarke earlier this year for harassment, alleging that the former sheriff had him stopped and arrested for shaking his head after recognising Mr Clarke during a flight.

“A reasonable sheriff deputy would have known that it is unlawful to stop, arrest and interrogate a citizen to investigate their political opinions,” Mr Black’s complaint reads.

The FBI agent’s filing reveals the agency was seeking to determine whether Mr Clarke had violated federal civil rights statutes and cited that “a factual basis that reasonably indicates the existence of federal criminal activity, the burden the FBI has in order to open an investigation”.

The document also reveals that a county investigation found it “credible” that Mr Clarke acted “in excess of his lawful authority to direct his deputies to stop and question Black without legal justification”.

Text messages detailed in court documents show Mr Clarke telling one of his deputies “no arrest unless he becomes an asshole with your guys”.

“Question for him is why he said anything to me. Why didn’t he just keep his mouth shut”? Mr Clarke wrote. “Follow him to baggage claim and out the door.”

After Mr Black filed his complaint, the court documents said an email sent from the account dcclarkecowboy@gmail.com told a subordinate of Mr Clarke that Mr Black “can go to hell”.

“The next time he or anyone else pulls this stunt they may get knocked out,” the email said, according to the FBI agent’s affidavit.

Representatives for the FBI’s Milwaukee office did not respond to messages seeking comment. The Milwaukee County Sheriff’s office has dismissed the county’s “fake investigation” as a “political witch hunt” intended to “ harass and bully Sheriff Clarke”.

“These fake news stories from the (Milwaukee) Sentinel Journal and their dweebs at the editorial board are so transparent that the casual observer can see this for what it really is,” the post said.

A staunch ally of Donald Trump who echoes the President’s law-and-order rhetoric, Mr Clarke announced his resignation earlier this year.

During his tenure, multiple inmates died in county jails, and a grand jury to recommended criminal charges against jail staff after an inmate died of dehydration.