Double-amputee Anthony Lowe, 36, who was black, was fatally shot on 26 January in the Los Angeles area.

Police say he threatened them after stabbing someone. Mr Lowe's mother said: "They murdered my son."

It comes amid renewed scrutiny of police killings after the death of Tyre Nichols in Memphis, Tennessee.

The incident involving Mr Lowe occurred in Huntington Park, and was caught on camera by bystanders.

The grainy video shows part of the confrontation with Mr Lowe holding a long shiny object and moving on the stumps of his legs away from officers. That clip does not show the shooting.

In a statement on 30 January, the Huntington Park Police Department said that officers had responded to a stabbing and the victim supplied a description of the suspect.

The suspect had allegedly left his wheelchair, approached the victim and stabbed him in the chest with a 12in butcher knife, before returning to the wheelchair and fleeing the scene.

The victim was left with "a life-threatening stab wound resulting in a collapsed lung and internal bleeding", the police statement said.

When officers caught up with Mr Lowe, according to the police statement, he "ignored the officer's verbal commands and threatened to advance or throw the knife at officers".

Police say that after two unsuccessful attempts to use Tasers to subdue Mr Lowe, they shot him.

Huntington Park Police Lt Hugo Reynaga told the Los Angeles Times that investigators had obtained video of the shooting from a nearby business, but do not plan to release the footage.