"The Department reviews the content of in-car video footage during the investigation of complaints, uses of force, vehicle pursuits, and other critical incidents. It generally does not, however, review the substance of DICVS footage in the absence of one of these investigations or reviews," according to the audit (PDF) from the commission's inspector general, Alexander Bustamante.

Bustamante said his office will continue monitoring the footage to ensure "that officers adhere to constitutional and legal standards as well as Department policy."

The audit comes as the recording of police activity—either by the public or by police video cameras—has become a national phenomenon in the wake of an 18-year-old unarmed teenager being shot and killed by a Ferguson, Missouri, police officer in August. Police departments nationwide are gobbling up dash cams and body cams. And the public is posting videos to YouTube of police activity regularly, often prompting investigations of activities that otherwise would have gone unnoticed without the mobile-phone footage.

Meanwhile, the Los Angeles Police Department dash cam policy requires officers using vehicles equipped with them to activate the cameras during all motor vehicle stops and when "practicable" during pedestrian stops. The report recommended that officers activate them during all stops, and the LAPD has agreed to change course.

The Office of the Inspector General (OIG) report found it quite helpful when footage was reviewed.

The advent of DICVS technology has been a great benefit to the Department and the OIG in investigating and reviewing events involving complaints of officer misconduct, officer-involved shootings and other uses of force, vehicle pursuits, traffic collisions, and other issues. Where available, in-car video or audio evidence has enabled the Department, in many cases, to refute false allegations, as well as to hold its employees accountable for those incidents where misconduct has occurred.

The dash cams include a front-facing camera and an internal camera pointing to the back seat. There is a built-in microphone and a portable one worn on an officer's belt. The camera turns on automatically if the light bar atop the vehicle is activated. The camera can also be activated on the system console or via a portable unit.

The audit found that it was easy for supervisors to review the footage, too.

"Each clip is searchable by an officer’s name or serial number, date, and can be viewed by authorized users on any network computer equipped with the DICVS software," the report said.

The department expects to have dash cams in most patrol vehicles by year's end.

In December, the LAPD announced it was purchasing 7,000 body cameras for LAPD officers to wear in the street.