CHICAGO (AP) — A 22-year-old Chicago man who was fleeing police had his back turned and appeared to drop a gun when an officer fatally shot him late last month, video released Wednesday shows.

Chicago’s independent police review board released video and other investigation materials pertaining to the March 31 killing of Anthony Alvarez, a day after letting his family see it.

Before the release, Mayor Lori Lightfoot called for calm in a repeat of just two weeks ago, when she did the same before the release of footage showing police kill 13-year-old Adam Toledo.

This video has been edited to stop at the moment just before Anthony Alvarez is shot. This may be disturbing for some viewers. Viewer discretion is advised.

In one of the clips posted on the Civilian Office of Police Accountability’s website, an officer’s body camera shows him chasing Alvarez. When Alvarez reaches a lawn in front of a house, the officer can be heard shouting, “Drop the gun! Drop the gun!” before he opens fire. Alvarez appears to drop a gun after five shots are fired and he falls to the ground.

As Alvarez lays on the ground, he asks, “Why you shooting me?” to which the officer responds, “You had a gun.” The officer later points to the weapon when other officers reach the scene.

It is clear in that shaky video that Alvarez had his back to the officer when he shot him. But it isn’t clear from the footage whether Alvarez had a gun or if he might have been turning at that moment. One officer can be heard saying there is a gun near Alvarez.

Alvarez’s family were provided the video on Tuesday. Todd Pugh, a lawyer for the family, said he watched the video, “And I saw a Chicago police officer shoot their son as he ran away from them.”

Lightfoot didn’t say what the video shows and authorities haven’t released the name or other details about the officer who shot Alverez, including the officer’s race. But a police report that COPA posted along with the video identified the officer as 29-year-old Evan Solano, a six-year veteran of the force.

In an unusual move, the head of the police officer’s union, John Catanzara, issued a statement in anticipation of the video’s release and what he said would be an outcry and “spin” about the shooting because Alvarez, whom he didn’t identify by name, was shot in the back.

“There is nothing wrong with this shooting just because the bullet struck the offender from behind,” Catanzara said in a video recorded statement.

“It is important for the public to look at this with an open mind,” he said.

Catanzara said the officer clearly saw Alvarez holding the weapon and that when he was shot, he was turning in the direction of the officer.

“The officer fears (he) would turn and fire because that’s the motion he was making,” Catanzara said.

Earlier this month, COPA released footage of the shooting of Toledo. It showed a white officer shoot the Latino teen as he turned toward the officer raising his empty hands less than a second after the teen tossed aside or dropped a handgun.

As in Lightfoot’s statement before the release of the Toledo shooting footage, her statement in the Alvarez case was made in conjunction with attorneys for the family and had essentially the same message.

“The parties are acutely aware of the range of emotions that will accompany the release of these materials and we collectively issue this statement and ask that those who wish the express themselves do so peacefully and with respect for our communities and the residents of Chicago,” the Wednesday statement said.

Police say Alvarez brandished a gun while an officer chased him on foot. As it did after the Toledo shooting, the department posted a photo on social media of the weapon it says was found at the scene.

But the department and COPA, which investigates all Chicago police shootings, have said little about the shooting, leaving unanswered questions about whether Alvarez fired at police and where on his body he was shot. Nor has the department said why the officer was chasing Alvarez.

After the two shootings, Lightfoot announced that the police department would implement a new foot pursuit policy for its officers. The U.S. Department of Justice recommended that the department adopt such a policy four years ago as part of its broader critique of Chicago’s policing practices.