A 34-year-old security guard has been charged with murder in San Francisco, District Attorney Brooke Jenkins said.

Prosecutors on Tuesday said they will ask Sefanaia Alatini be held without bail after killing someone during an argument at a parking lot in the city’s Tenderloin neighborhood.

Jenkins said security camera video caught the shooting as it happened and claims Alatini got into some kind of confrontation. Alatini at one point left the scene and returned with a gun, according to Jenkins.

“At the point that the victim saw the defendant was holding a firearm, the victim pepper sprayed in the direction of the defendant before walking away,” Jenkins said. “It was at that time that the defendant pointed the firearm at the victim – shooting him in the back.”

The District Attorney’s Office is not providing any information on the person killed.

Even though there are indications from initial reports the shooting started from an argument, Jenkins said they do not believe the incident was self defense by the shooter.

“What we did see is a brandishing of a firearm prior to the victim ever displaying pepper spray and or using that pepper spray,” Jenkins said. “So actually in that sense, it would support the victim having used some form of self defense.”

NBC Bay Area on Tuesday reached out to the private security company that patrols the parking lot where the deadly shooting occurred, but did not get a response. NBC Bay Area also reached out to the Tenderloin Community Benefit District for comment and also did not get a response. Several of the district’s trucks were seen parked in the lot on Tuesday.

Alatini is facing a single charge of murder, committing a crime with a gun and being a felon in possession of a gun. He is scheduled to be arraigned on Wednesday.