LITTLE ROCK, Ark. — Little Rock's police chief on Wednesday sued the local police union, two assistant chiefs and several officers, accusing them of conspiring to try and force him out of his job.

The federal lawsuit by Chief Keith Humphrey is the latest round in an escalating public fight within the department that is centered on his response to the fatal shooting of a Black motorist by a white officer last year.

The defendants include Charles Starks, the white officer who Humphrey fired over the shooting of Bradley Blackshire. Starks was later reinstated by a judge but submitted his resignation in September.

The lawsuit accuses the Little Rock Fraternal Order of Police and its executive board of orchestrating a campaign against the chief that included lawsuits accusing him of retaliating against assistant chiefs who testified against him in hearings over Starks' firing. It also accuses the union, Starks and a local blogger of publishing false stories online about him.

"This is about the right thing. ... It's not about Keith Humphrey," the chief said at a news conference at a Little Rock church. "You don't treat people this way."

In a statement, the FOP said it would "vigorously defend" its members "against all allegations and stand by the record of selfless community service of the law enforcement officers named in the suit as well as our organization itself, which has been a fixture in the Little Rock community."

And an attorney for several officers named in the lawsuit called it an effort by the chief to silence his critics.

"It's sad, unfortunate, unprecedented that the chief would be suing his own employer and his own officers," attorney Chris Burks said of the lawsuit, which also named a Little Rock human resources official as a defendant.

The Fraternal Order of Police approved a vote of no-confidence resolution on Humphrey in June, citing the lawsuits and complaints against him. Humphrey, who is Black, said Monday that his lawsuit wasn't about race, though it claims that the union is treating him differently because of his race and his policing philosophy.

Humphrey was hired in 2019 by Mayor Frank Scott, who is the city's first popularly elected Black mayor. Humphrey told reporters that he hadn't talked with the mayor about his lawsuit before its filing.

Scott declined to comment directly on the suit, but said in a statement that the city "remains focused on strategically addressing crime and ensuring that our officers are building relationships with the communities they serve, in the true fashion of a 21st century police department."

Humphrey fired Starks over the Blackshire shooting, despite recommendations from the officer's supervisors that he stay on the force. In his resignation letter, Starks accused the chief of making his working conditions "intolerable" since he was reinstated.