The city of Chicago released a video Tuesday showing the fatal shooting of black 17-year-old Laquan McDonald by a white police officer. Here is what is seen on the relevant portion of the video, which runs for less than 40 seconds and has no audio:

McDonald swings into view on a four-lane street where police vehicles are stopped in the middle of the roadway. As he jogs down the street, he appears to pull up his pants and then slows to a brisk walk, veering away from two officers who are emerging from a vehicle and drawing their guns.

Almost immediately, one of the officers appears to fire from close range. McDonald spins around and crumples to the pavement. The second officer simultaneously lowers his weapon.

The car with the camera continues to roll forward until the officers are out of the frame. Then McDonald can be seen lying on the ground, moving occasionally. At least two small puffs of smoke are seen coming off his body as the officer continues firing.

In the final moments, an officer kicks something out of McDonald's hands. Police have said the teen had a knife.