A couple of weeks ago, I put up a post looking at the main problem with relying on video from video cameras mounted to police officers and to the dashboards of their squad cars — there have been a number of police misconduct cases in which video has gone missing, or in which cameras have malfunctioned at critical times.

It doesn’t matter how potentially beneficial the technology is if the cops using it are going to undermine its transparency value, and if police agencies and courts don’t subsequently hold those cops accountable.

Currently, the Los Angeles Police Department is experimenting with body cameras for its police officers. It’s a good step toward more transparency. But it’s critical that the department has and maintains the public trust. The citizens of L.A. need to know that the video from these cameras will be there not only to exonerate good cops accused of wrongdoing, but also to implicate bad cops. If cops can simply turn off their cameras at will, or if incriminating video can be destroyed without consequence, the cameras become tools of corruption, not of transparency.

To that end, this is a troubling sign:

Los Angeles police officers tampered with voice recording equipment in dozens of patrol cars in an effort to avoid being monitored while on duty, according to records and interviews.

An inspection by Los Angeles Police Department investigators found about half of the estimated 80 cars in one South L.A. patrol division were missing antennas, which help capture what officers say in the field. The antennas in at least 10 more cars in nearby divisions had also been removed . . .

A federal judge last year formally ended more than a decade of close monitoring of the LAPD by the U.S. Department of Justice. The judge agreed to lift the oversight, in part, after city and police leaders made assurances that the LAPD had adequate safeguards, such as the cameras, in place to monitor itself . . .

The cameras, which turn on automatically whenever an officer activates the car’s emergency lights and sirens or can be activated manually, are used to record traffic stops and other encounters that occur in front of the vehicle. Officers also wear small transmitters on their belts that relay their voices back to the antennas in the patrol car. Regardless of whether they are in front of the camera, officers’ voices can be recorded hundreds of yards away from the car, said Sgt. Dan Gomez, a department expert on the recording devices . . .

Worse, LAPD brass knew about the problem, took no disciplinary action and kept it under wraps.

LAPD Chief Charlie Beck and other top officials learned of the problem last summer but chose not to investigate which officers were responsible. Rather, the officials issued warnings against continued meddling and put checks in place to account for antennas at the start and end of each patrol shift.

Members of the Police Commission, which oversees the department, were not briefed about the problem until months later. In interviews with The Times, some commissioners said they were alarmed by the officers’ attempts to conceal what occurred in the field, as well as the failure of department officials to come forward when the problem first came to light.

“On an issue like this, we need to be brought in right away,” commission President Steve Soboroff said. “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.”

Seems like another argument for the “Missing Video Presumption.” Or I guess in this case, the “Missing Audio Presumption.”