Los Angeles police officers removed antennas from police cars in several predominantly Black neighborhoods to disable the recording equipment and avoid being monitored while on duty, according to an inspection by LAPD investigators.

The department review found about half of the 80 cars in the Southeast division—which includes Watts and the Jordan Downs and Nickerson Gardens housing projects—were missing the antennas that help capture what officers say in the field. The review discovered at least 10 more cars in nearby divisions also had antennas removed.

Members of the Police Commission, which oversees the department, said they were alarmed by both the actions of the officers and the failure of the department to reveal their actions when they were first detected.

“On an issue like this, we need to be brought in right away,” commission President Steve Soboroff told the Los Angeles Times. “This equipment is for the protection of the public and of the officers. To have people who don’t like the rules to take it upon themselves to do something like this is very troubling.”

But LAPD Chief Charlie Beck said the department did not purposely try to hide the matter from the commission and pointed out that he has always been a strong advocate of the recording devices. LAPD officials decided it would be futile to try to figure out which officers were responsible for removing the antennas, since so many of them use the cars during their shifts. Instead the department warned officers about removing the antennas and put checks in place to account for the equipment at the start and end of each patrol shift.

One of the main reasons a federal judge agreed to lift the Department of Justice’s oversight of the notoriously corrupt LAPD last year, after more than a decade, was because of safeguards such as the cameras.

The cameras turn on automatically whenever an officer activates the car’s emergency lights and sirens or can be activated manually. They are used to record traffic stops and other encounters that occur in front of the vehicle.

In addition, officers wear small transmitters on their belts that relay their voices back to the antennas in the patrol car. Sgt. Dan Gomez, a department expert on recording devices, told the Times that regardless of whether they are in front of the camera, officers’ voices can be recorded hundreds of yards away from the car—but that distance is severely curtailed by as much as a third without the antennas.