The California attorney general's office will review the decision not to charge a security guard in the fatal shooting of a suspected shoplifter last month at a Walgreens store in downtown San Francisco, it said Tuesday.

The review comes after the San Francisco district attorney's office said last week that security guard Michael Anthony would not face criminal charges because he acted in self-defense when he shot Banko Brown on April 27.

Brown's family attorney John Burris, who previously described the guard's actions as "way beyond what was reasonable and necessary," sent a letter to the attorney general's office last week requesting the investigation.

"We can confirm that our office has agreed to review whether the San Francisco District Attorney's decision not to file charges was an abuse of discretion," the California attorney general's office told CNN in a statement.

The killing and lack of charges spurred protests in San Francisco amid a larger debate over criminal justice in the Northern California city, with demonstrators marching to demand justice for Brown.

A written report from the district attorney's office released last week said Brown had repeatedly threatened to stab the security guard before the shooting. Police did not find a knife in Brown's possession, the report states, but prosecutors still determined his fear was reasonable.

"Given the totality of the circumstances, including the threat that Anthony believed, and could reasonably believe, the evidence shows that Brown's shooting was not a criminal act because Anthony acted in lawful self-defense," the report states. "Thus, Anthony is not criminally liable for the death of Brown."

Surveillance camera video of the incident shows Brown attempting to leave the store before being stopped by the security guard, identified by police as Anthony. Brown then shoves the guard, leading to a physical altercation, the video shows.

Brown is held on the ground by the guard but released after about a minute, the video shows. Brown starts to leave but appears to turn around and move toward the guard who then shoots him, the video shows.

Brown repeatedly threatened to stab Anthony during the fight, the security guard said in a videotaped interview with police.

"I felt like I was in danger. I felt like I was going to be stabbed," he said.

The district attorney's report notes that self-defense applies when a person has a reasonable belief they are in imminent danger of being killed or suffering great bodily harm. "There is no evidence to contradict that Anthony's fear was honest," the report states.

San Francisco District Attorney Brooke Jenkins welcomes the attorney general's review and "will assist and cooperate as needed," she told CNN in a statement Tuesday.

"I heard the public's concerns and we released a comprehensive analysis and report that included investigative records, witness statements and video evidence, so the public could see all of the facts and details and understand how we arrived at our decision. We provided the highest degree of transparency possible that we could with this case," she said.

Burris said his clients are pleased with the decision, as they think a review by another prosecutor is justified.

No time frame was shared on when the investigation might be completed, Burris said.