An amateur video of San Francisco police surrounding a suspected knifeman and gunning him down in a hail of bullets has gone viral on social media and provoked outrage.
The 15-second video clip taken with a mobile phone by a passenger aboard a bus parked nearby shows what is allegedly a use of excessive force by the police.
It starts with a man wearing a dark jacket walking and leaning against a wall as he is surrounded by at least seven police officers with their weapons drawn.
As the man ignores their commands and start to wobble away, the officers open fire.
The footage ends there as the person filming it ducked for cover, but 20 gunshots could be heard.
A press release by the San Francisco police department, tweeted on their account @SFPD, said the incident happened on Wednesday afternoon near the Bayview station.
Police claimed the dead man matched the description of a stabbing suspect and that officers opened fire to prevent him from harming others.
They said the man did not stop even after they doused him with pepper spray and fired non-lethal bean bags at him. He also allegedly tried to approach an officer with knife drawn.
“As the suspect had already demonstrated that he was a danger to others by having stabbed an earlier victim, the officers could not allow him room to harm anyone else,” police said.
No knife is, however, seen in the short video clip which captured only part of the incident.
Police in the United States have come under intense criticism for using excessive force against suspects--many of them black--and often with lethal effect.
Earlier this week, Chicago’s mayor fired the city police chief after a graphic video of a white officer fatally shooting a black teenager 16 times sparked a week of protests.