LOS ANGELES (AP) — Los Angeles police say three officers fired on and killed a man on the city's Skid Row because of a struggle over one of the officers' guns.

Police say graphic video of the incident that was shot by a bystander and widely circulated on social media a few hours after the incident Sunday will be used in their investigation.

Police Cmdr. Andrew Smith said the three police officers including a sergeant shot the man as they struggled on the ground for control of one of the police officer's weapons, after a stun gun proved ineffective. They were answering a report of a robbery.

The video shows four officers struggling with the man amid the tents and cardboard of the Skid Row sidewalk.

At one point the word "gun" can be heard, followed by the sound of about five gunshots.