Garrett Rolfe will remain on administrative leave until the criminal charges against him are resolved, Atlanta Mayor Keisha Lance Bottoms said.
“I know a con game when I see it," the civil rights activist said of police holding on to footage of the North Carolina shooting.
Amber Guyger's lawyer has asked to acquit her of murder or to substitute in a conviction for criminally negligent homicide, which carries a lesser sentence.
The family, which was allowed to see just 20 seconds of the footage, called his death an execution.
They said a snippet of body camera footage shows Brown with his hands on his car's steering wheel when police shot him in the back of the head.
While the body camera footage has not been released, emergency scanner traffic suggests that police shot and killed Andrew Brown Jr. while he was trying to drive away.
The Knox County district attorney said Officer Jonathon Clabough acted in "self-defense" after 17-year-old Anthony J. Thompson Jr. fired a handgun.
Police officers in Ohio, California and North Carolina have killed Black people since Derek Chauvin was found guilty.
Nicholas Reardon, a white officer and U.S. Air National Guardsman, fired four shots at the teen on Wednesday. An investigation into the shooting is underway.
Michael Slager told the judge that he was never made aware of a plea deal that would have cut years off his sentence for the 2015 shooting of Walter Scott.