Four Chicago police officers were fired Thursday for allegedly covering up the fatal shooting of black teenager Laquan McDonald by a white officers five years ago.

The nine-member board Chicago Police Board found the officers exaggerated the threat posed by the 17-year-old McDonald to justify his shooting by officer Jason Van Dyke.

The board voted unanimously to fire Sgt. Stephen Franko, and officers Janet Mondragon and Ricardo Viramontes. All but one voted to fire Daphne Sebastian because of violations of department rules. She was not found to have made false reports.

Six other officers originally singled out for investigation left the department before they could be disciplined.

Patrick Murray, first vice president of the Chicago Fraternal Order of Police, criticized the board’s decision, saying the officers did nothing wrong.

“It is obvious that this Police Board has out-served its usefulness,” he said, the Chicago Tribune reports.

Van Dyke is serving a more than six-year prison term for second-degree murder and 16 counts of aggravated battery with a firearm.

The officer, who was convicted last year, had confronted McDonald after police were called to a parking lot on the southwest side of Chicago in response to reports of a person breaking into trucks and stealing radios.

Officers arrived to find the teenager, who was allegedly high on PCP, walking erratically in the street with a small knife.

Van Dyke opened fire within seconds of getting out of his squad car, shooting the teen 16 times, many after McDonald had fallen to the ground. The shooting was captured on police dashcam video.

In 2016, Police Superintendent Eddie Johnson accused the officers of either giving or approving knowingly false statements. None of the four were charged criminally, but were assigned to desk duty. The dismissals can be appealed through a lawsuit.

A Cook County judge acquitted three other officers in January of conspiracy, obstruction of justice and official misconduct charges in the case. The judge rejected the contention that a video of McDonald’s death proved police officers staged a cover-up.

Franko was accused of approving false police reports that McDonald attempted to stab Van Dyke and another officer and had in fact injured Van Dyke.

Mondragon was accused of falsely reporting that she did not see the shooting because she was shifting the gear of her squad car. She was also accused of incompetence for not inspecting the video equipment in her car to see if it was working and recording events.

Viramontes was accused of reporting that McDonald continued to move after he shot and that he tried to get up with the knife still in his hand. He maintained that view even when an investigator showed him a video of the shooting.

Sebastian was determined to have given misleading and inconsistent statements to investigators that McDonald turned toward Van Dyke and another officer with a knife in a motion toward them.

The case created an uproar within the Chicago criminal justice system. Then-Mayor Rahm Emanuel fired police superintendent, Gerry McCarty, while Cook County State’s Attorney Anita Alvarez, the top prosecutor, lost her re-election bid.

The incident also led a U.S. Justice Department investigation to find a “pervasive cover-up culture” that prompted plans for far-reaching police reforms.

Contributing: Associated Press