This dash-cam footage had no audio. Photo: Chicago Police Department via Getty Images

After the notorious video of Laquan McDonald getting shot by Chicago police officers 16 times went viral last November, investigators have been making their way through the other videos of the scene. In doing so, they’ve discovered that three of the dash cams pointed at McDonald that day did not record video, and others had no audio. Now a Chicago Police Department audit reveals that many of the department’s dashboard cameras have been deliberately sabotaged.

Last month the CPD found that 80 percent of its 850 dash cams do not record audio, and 12 percent don’t record video either. The CPD has blamed the failures on “operator error or in some cases intentional destruction,” and a close reading of that review by DNAinfo Chicago reveals the extent of the latter. Officers frequently tampered with dash cams, stashing microphones in their glove boxes or pulling out batteries. Some dash cams were found with their antennae deliberately destroyed, and others had had their microphones removed altogether.

DNAinfo also describes a months-long repair time for dash cams that experienced “intentional destruction.” For example: Jason Van Dyke, the officer who shot and killed McDonald and has been charged with first-degree murder, brought in his dash cam in early 2014 to have a wiring problem fixed, and got it back three months later, on June 17. The very next day, the dash cam was broken again. This time it took until October 8 to fix what appeared to be intentional damage. Less than two weeks later, his dash-cam footage of the McDonald shooting (which differs from the viral video we all saw) had no sound. Police records show that the microphones in his car had never been synced up to the camera.

In December, Chicago’s interim police superintendent, John Escalante, started handing out reprimands and suspensions of up to three days to officers who damaged their dash cams. Each week’s video is receiving an audit from the superintendent’s office. A police spokesperson says the department has seen a 70 percent increase in the number of video uploads by officers since penalties have been enforced.