Crowds of angry people formed claiming the man was unarmed when he was shot from behind in the Bayview District, but police are trying to put those claims to rest.
Following the shooting, police learned there was video that showed the immediate aftermath. Police say the suspect fired at officers first, but investigators could not initially find the weapon.
Protesters mixed with police officers Sunday afternoon at the scene of the Bayview District shooting at Third and Oakdale. Service on the Muni T-Line was briefly stopped.
"We lost a life out here," said resident Pladee Clayton. "That's what everybody's upset and everything, over an African-American couldn't pay his fare."
Police announced a break in the investigation on Sunday. After searching rooftops for a gun pointed at officers by the suspect, the answer may have come from a video posted on the website YouTube. The video shows police moments after the shooting and what appears to be a silver gun just feet from the suspect.
"Someone picked up the firearm that the suspect had shot with and ran southbound up the street with it," San Francisco Police Chief Greg Suhr said. "Luckily, someone else in the crowd took video...and officers have been able to track that firearm and we believe we have it in custody."
Two San Francisco police officers were on the Muni platform at Third and Palou Saturday afternoon. After some recent shootings, they were assigned to a violence reduction program and were making sure some passengers had paid their fares.
They briefly detained a 19-year-old subject, but officers say he bolted while firing several shots in their direction.
"Although the suspect was firing back into Mendel Plaza that was full of people, including children, nobody else was injured by the gunfire and officers were able to beat back the attack, fatally injuring the suspect," Suhr said.
However, some residents don't agree with the shooting, even if police say it was justified.
"Regardless of if they found a gun or not, it's the fact they chased him from the T-train over a transfer, and while there's real crime going on," said resident Debray Carpenter.
Police confiscated surveillance video from a Dollar Store on Third and Palou. Investigators say they will be looking at images from nearby cameras, including cameras on the Muni platform.
"As it is now, the investigations have to be completed, but the information we have is you have somebody shooting at a police officer," San Francisco Mayor Ed Lee said. "That, of course, is very dangerous and officers had to not only protect themselves but protect the public."
Police have not identified the 19-year-old suspect who was killed, but did confirm with ABC7 News that the suspect was a person of interest in a South Seattle shooting last week in Washington state. The shooting there wounded four people, including a pregnant woman who died from her injuries. Police also say the suspect had two felonies in Washington state and was currently on parole.
Investigators will be conducting tests on the firearm to determine if it was in fact set off and if it is the weapon they say they recovered.