The incident was initially reported by San Francisco Municipal Railway officials at 4:50 p.m. as police activity near Third Street and Paul Avenue.
The suspect was involved in an earlier stabbing nearby, according to police. A video posted to the social media site Instagram, apparently filmed by a bystander aboard a Muni vehicle, appears to show a man limping on the sidewalk and surrounded by police officers.
In the video, it appears a woman in the foreground who is also taking a video of the incident, urges the man to "Just drop it. Just drop it, please," then seconds later a number of shots ring out.
The officer-involved shooting comes the same evening the San Francisco Police Commission was considering policies for body-worn cameras by the Police Department's officers. The cameras, not yet worn by officers, are slated to be deployed in San Francisco sometime in 2016.
Police say they believe the suspect was involved in a stabbing around 3:50 p.m. earlier in the afternoon.
"We had a walk-in victim that had been stabbed in the shoulder on the 6600 block of Third Street. Officers from the Bayview who responded, were told by a witness to the stabbing that the suspect was still in the area," said San Francisco Police Chief Greg Suhr.
Police began looking for the suspect and finally encountered the man near Third St. and Gilman Avenue. Officers told him to drop the knife, but according to Suhr, he didn't. "They deployed the standard bean bag guns several times striking the suspect. He did not drop the weapon," said Suhr.
Officers then used a higher powered bean bag gun to disarm the suspect, knocking him down, but again he didn't drop the knife.
"This suspect had already demonstrated by committing a felony aggravated assault that he was a danger to others. So he could not be allowed to move away from the scene," said Suhr.
That's when the chief said officers feared for their lives and fired several shots. This part was captured on cell phone video where you see the person with the camera ducking for cover.
"One of the officers cut off his path. He went toward the officer and that officer and four other officers fired in defense of the officer he was moving towards," said Suhr.
One man, who was not an eyewitness to the scene but viewed the video, interpreted the confrontation differently.
"Young man was up against the wall he was backing up never did he approach the police in any form or way. He was backing up if anything and then he was shot," said a man who goes by "G."
He said he's angry at the officers' actions and that his heart is with the victim's family.
"I just want to say rest in peace to the young man. I've never seen him I don't know him. God bless him and his family," said G.
It's unclear if the knife recovered at the scene is the same used in the stabbing, according to police. The victim in the stabbing was wounded in the shoulder and is expected to survive.
Video embedded below is graphic.