Protester posters sit outside the building where a police panel hearing was held in April for the officer who fatally shot motorcyclist Terrence Sterling in 2016. (Peter Hermann/The Washington Post)

A D.C. police officer the city has decided should be fired for fatally shooting a motorcyclist in 2016 says members of an administrative panel that upheld his punishment unfairly prejudged the case.

Officer Brian Trainer also argues that one of the police officials on the tribunal should either have recused himself or disclosed that he had fatally shot a motorist in Virginia in 1996.

These assertions are contained in a 50-page appeal to D.C. Police Chief Peter Newsham. The chief has until the end of the week to decide whether he will uphold the decision to terminate Trainer in the fatal shooting of 31-year-old Terrence Sterling or allow the officer to remain on the force.

Trainer shot Sterling during an attempted traffic stop. The department found the shooting to be unjustified. Trainer argued that he was in danger.

“Officer Trainer’s due process rights have been so gutted that the only remedy” would be clearing the officer, his attorney James W. Pressler Jr. wrote in the appeal, a copy of which he provided to The Washington Post. Pressler wrote that panel members “prosecuted the case” while “shirking their obligation to remain neutral and impartial.” He contends the panel was unfairly influenced by public comments from Mayor Muriel E. Bowser (D) and Newsham that Trainer should quit. The city had reached a $3.5 million settlement with Trainer’s family.

Pressler also said that the failure of Capt. Robert Glover to disclose his own fatal shooting of a motorist prevented challenging the tribunal member for possible bias. “In light of Captain Glover’s surprisingly adversarial behavior toward the defense witnesses during the hearing, it simply cannot be argued that he was not influenced in some way by this prior shooting incident,” the attorney wrote.

Terrence Sterling, 31, of Fort Washington, Md., was fatally shot by a D.C. police officer during an attempted traffic stop in September 2016. (Family photo)

Newsham has declined to comment, saying it would be improper to speak about a case he is reviewing. Glover also declined to comment.

The department’s chief spokesman, Dustin Sternbeck, said Pressler was informed of the tribunal’s participants in December 2017.

“No objections were made by his counsel in the five months leading up to the trial or at any time during the three-day hearing,” Sternbeck said in a statement. “It was only after the record closed and the panel issued the termination decision that Officer Trainer’s lawyer objected to Captain Glover’s participation.”

The police panel’s members heard testimony for three days in May before they unanimously ruled that Trainer violated department rules when he shot Sterling near the entrance to the Third Street Tunnel on Sept. 11, 2016. Trainer testified that Sterling deliberately drove at his cruiser and struck a side door, pinning his leg and prompting him to fire to prevent serious injury.

Trainer’s attorney said he does not believe that Newsham will overturn the decision and promised to push forward in the appeal process. If Newsham upholds the firing, Trainer can appeal to an arbitrator, then to the District’s employee relations board and then in court. Trainer is scheduled to be terminated June 21.

The shooting occurred early in the morning after Trainer and his partner, in a marked police car, spotted Sterling at an intersection. Trainer testified at the hearing that Sterling stopped his motorcycle in front of the cruiser at a red light on U Street NW, glanced back at the officers and then bolted through the light. The driver, Officer Jordan Palmer, took off after him, ignoring orders not to chase the motorcycle, and engaged in an unauthorized pursuit to Third and M streets NW, more than 30 blocks away.

Sterling’s family has said they believe the HVAC technician from Fort Washington, Md., had been at a party and was headed home.

Police noted that Sterling had been reported driving at speeds of more than 100 mph, and had marijuana and twice the legal limit of alcohol in his system. The officers saw Sterling near a tunnel entrance. Police officials said the cruiser blocked the motorcycle, which is against department rules, although Trainer and Palmer denied this.

Trainer said Sterling looked in his direction, turned the bike’s handlebars toward him, revved the engine and then shot forward, appearing to aim directly at his cruiser as the officer began to step out of the car, his gun already drawn.

The officer said he put his right leg out of the cruiser and was trying to stand up. As the motorcycle got closer, he said he tried to get back into the car but the motorcycle’s front tire hit the door, trapping his leg between the door and the car frame. He testified that he fired twice as he fell back into the car. Trainer failed to turn on his body camera before the shooting.

The detective leading the inquiry concluded that Sterling was probably trying to maneuver around the cruiser but his path was cut off when Trainer opened the door. Panel members questioned why Trainer had pulled his gun before he perceived a threat.

Pressler argued that the panel “consistently asked questions and made comments critical of Trainer and his witnesses.” He cited one comment by Glover: “I wouldn’t get into a [police] car with you tonight and go out on patrol with you.”

Before the May hearing, Pressler asked the panel if any member would have a problem finding for his client “if the evidence supports those findings.”

The panel’s chair, Cmdr. Morgan Kane, refused to allow him to question each member. “We’re professionals,” she said.

Pressler responded in his appeal: “This panel was neither neutral nor impartial.”

He said it was not until after the panel had made its decision that he learned Glover had fatally shot a motorist on Interstate 95 in Fairfax County in August 1996.

According to a Washington Post article, Glover fatally shot Auguster A. Carter, 48, who had been stopped by a Virginia state trooper who saw him driving erratically and suspected he was under the influence of alcohol or drugs.

Carter tried to drive away with the trooper hanging on the door. Glover, who was headed to work in the District, stopped and shot Carter through a side window.

Carter’s employer told The Post that he was a diabetic. Authorities said Carter had cocaine and marijuana in his system, and cocaine and marijuana were found in the vehicle. Fairfax County Commonwealth’s Attorney Raymond F. Morrogh said there is no record of Glover being charged in the shooting.

Pressler said he should have had a chance to learn whether the captain could judge “fairly and impartially” before the hearing commenced.