Only Albuquerque police really know what happened early one April morning in 2014, when officer Jeremy Dear shot and killed 19-year-old Mary Hawkes, a suspected car thief, after a foot chase.

Dear’s body camera was off, he said, and the footage from body cameras of his fellow officers doesn’t give a clear picture of the teenager’s death. While Hawkes’ family accused police of a cover-up, their best evidence—the footage from the other body cameras—is either conspicuously absent or incomplete.

Now, one former police department records keeper is claiming the damaged or missing footage was deliberate, and alleging proof lies in the computer software—called Evidence.com —that the department uses to manage its body cameras.

“I have reviewed the lapel camera video [which two officers] provided to APD Forensic after the shooting of Mary Hawkes,” Reynaldo Chavez said in a court statement. “Based on my knowledge of Evidence.com , I can see that [one officer]’s lapel camera video has been altered by changing the gradient of the resolution on the video. I can see as much as the first twenty seconds of [the other officer’s] video has been deleted.” . . .

Evidence.com also allows users to edit and delete body camera footage. The tools can theoretically be used to highlight important frames of a video, or blur faces in order to protect identities. But Chavez, who had extensive training with the program, claims he saw the editing software put to more sinister use.

“I was able to see, via the Evidence.com audit trail, that people had in fact deleted and/or altered lapel camera videos,” he alleged in the affidavit, accusing detectives of training officers, particularly “those in the Forensics Unit and the Major Gangs unit how to edit video, meaning you could delete video and add images and blur video and/or corrupt video so they were either not usable or altered.”

Chavez claims that officers in these units were allegedly instructed not to file crime reports until after their body camera footage was viewed. If the footage presented the officers in a good light, Chavez said, they could release the film in the name of transparency. If the footage was problematic, they were allegedly encouraged to claim a faulty camera.