A video appearing to show police cornering a mentally ill and blind man before he was shot dead has been released by the victim's family.
The CCTV footage purportedly shows James Hall surrounded by heavily armed officers in a petrol station and then collapsing to the ground as he is gunned down.
The clip was released after his family announced it was suing the police department in California for using “excessive force”.
“James was not observed by family, friends, or those who knew him as having violent tendencies because of his mental illness,' said attorney Ben Meiselas, of Geragos & Geragos in Los Angeles.
“The family is also puzzled and alarmed by characterisations of the incident as an ‘armed robbery’ when the only facts released were that James was outside the Chevron station the entire time until police arrived and drew their guns.”
A Fontana Police Department statement said it was responding to a robbery at around 4.15am on 22 November, 2015.
When officers arrived that scene, it said Mr Hall was holding a knife and large rock upon arrival.
The 47-year-old, who the family say was legally blind and suffered schizophrenia symptoms and mood disorder, can be seen holding objects in the video.
The lawyers’ court papers filed on 8 December, given to The Independent by Mr Meiselas, list the 20 officers by name that they say were involved, and say one had an assault rifle, and that a police dog was deployed.
The lawsuit said he was “startled” and “cowered” at the back of the store which was empty at the time but for a clerk.
Geragos & Geragos, which has worked with Michael Jackson, singer Chris Brown and Lionel Ritchie’s daughter Nicole, said 20 officers are being sued.
Mr Hall, who is survived by four siblings, was a “peaceful person” and was reportedly given a community service award in 2010 for helping rescue a four-year-old autistic child, they added.
In November 2015, Mr Geragos told the Fontana Herald News: “We have grave concerns regarding the police practices leading up to this tragic death.”
Up until 28 July, 613 people had been killed by US police in 2016, and The Guardian claims 1,091 were killed by the end of the year.
In the 12 months to March 2016, British police discharged their firearms on seven occasions.
A Fontana Police Department statement reads: "We have every confidence in the investigative process and await the conclusion."