Protester posters on April 11 in Washington. (Peter Hermann/The Washington Post)

THE HEARING spanned about 40 hours over three days. Evidence included more than 1,500 photographs and thousands of pages of reports. A dozen witnesses testified. The administrative proceedings into the fatal police shooting in the District of a 31-year-old motorcyclist was a much-needed public airing of the troubling events that occurred almost two years ago. It’s good that the D.C. police department recognized the importance of transparency, and that it has moved to hold accountable the officer whose actions caused what was determined to be an unnecessary death.

The three-member panel of senior police officials who examined the shooting of Terrence Sterling, it was announced May 11, has concluded that the shooting was not justified and that the officer, Brian Trainer, should be terminated. The findings mirror those of the department’s earlier internal investigation. The officer was not charged criminally because federal prosecutors said there was insufficient evidence. But that left unanswered questions about whether appropriate action was taken and police policy followed.

Searing testimony during the April proceedings detailed how what started out as a simple traffic infraction in the early-morning hours of Sept. 11, 2016, spiraled into an unauthorized high-speed chase and a confrontation that ended with police bullets fired at an unarmed man. Mr. Trainer and his partner, city attorney Nada Paisant told the tribunal, “were pissed off they couldn’t effectuate a traffic stop. They were going to stop Mr. Sterling with whatever means necessary.” Members of the panel, The Post’s Peter Hermann reported, were unsparing in expressing frustration at how training, regulations and orders were ignored. Among the rules broken: shooting at a moving vehicle and failing to turn on the police body camera.

Mr. Trainer, who has said he feared for his safety when he fired, plans to appeal the termination to D.C. Police Chief Peter Newsham. The chief is not seen as likely to overturn the police tribunal’s ruling. The next step, as spelled out by the union contract, would be arbitration, then the District’s employee relations board and, eventually, the court system. It is a process, a 2017 Post investigation found, with no room for even minor error by the department, with the result that police are sometimes forced to rehire officers even when there has been misconduct. The Sterling case clearly is far from over, but the rigor and openness so far shown by the department in handling this matter should inspire public confidence.