Body cameras can be a powerful tool. But not all police forces carry them.

Even experts who support the use of body cameras warn that the images can sometimes be misleading or open to different interpretations. “People disagree about police work and will continue to disagree about what exactly a video shows,” Seth W. Stoughton, a law professor at the University of South Carolina and former police officer, told The New York Times for a video study from 2016.

The January incident outside of Atlanta occurred in DeKalb County’s South River Forest, where the city plans to build an 85-acre training center on land it owns. The project has sparked months of intense protests from activists who want to preserve the nearly 400 hectare forest and oppose what they call the further militarization of the police.

Researchers have said that officers from the logging task force tried to command Terán out of a tent in the woods, after which the activist shot a state agent, prompting other officers to return fire. The Georgia Bureau of Investigation has said gunshot residue was found on the activist’s hands, and records show that Terán purchased the firearm used to shoot the trooper.

But members of the activist’s family claim that Terán, who was non-binary and known to forest activists as Tortuguita, or Little Tortoise, was a pacifist. The family ordered their own autopsy, which revealed that Terán had been shot while sitting cross-legged, hands raised. The family’s autopsy found no trace of gunshot residue, nor did an official autopsy performed by the DeKalb County coroner find that Terán had suffered at least 57 gunshot wounds.

While investigators say no video footage of the shooting was captured on camera, audio was. Footage released by the Atlanta Police Department of officers wearing body cameras and located in a different part of the woods includes the sounds of distant gunfire and the voices of officers discussing friendly fire. Activists seized on the exchange, suggesting troopers injured one of their own.

In a statement after the footage was released, the state bureau acknowledged that “at least one statement exists in which an officer speculates that the trooper was shot by another officer in crossfire.” But it added: “Speculation is not evidence. Our research does not support that statement.”

The agency turned the case over last month to a special prosecutor, George Christian, who is the prosecutor for the Mountain Judicial Circuit in northeastern Georgia. In a statement this week, Mr Christian said he was in the process of establishing “whether the use of deadly force was authorized or not”, and that he had not finished reviewing the evidence. He didn’t say when he would make a decision.