By Audrina Bigos

(CBS) — Chicago police officers in some cases are sabotaging dash cams, but the city’s interim police superintendent says a crackdown has been effective.

CBS 2’s Audrina Bigos reports.

When Chicago teen Laquan McDonald was shot and killed by a Chicago police officer, five squad cars were on scene. Only two cars were recording video of the encounter.

None of them were rolling sound. If the dashcams were working properly and not tampered with, “theoretically you would have heard any verbal directions that were being given,” says Interim Police Supt. John Escalante.

There was no sound, however. Escalante says that’s one example of a bigger problem.

The dashcam technology dates back to 2007.  Because of technical issues, Escalante says, 12 percent of the cameras are not working on any given day.

“Other times, it’s human error, and it’s accidental, legitimate accidental human error; but there are other times it’s deliberate, people deliberately trying to circumvent the system,” Escalante says.

That’s when officers don’t activate the system when they should. Escalante disciplined 22 officers in a one-month period after the dash-cam fallout in the shooting death of McDonald.

Officers were cited for audio issues, not uploading video at the end of a shift, and not inspecting cameras to make sure they worked.

Since the crackdown, he’s seen an 80 percent increase in the amount of officers uploading video properly, on a daily basis, Escalante says.

The next step for the department: rolling out body cameras. Seven districts will be part of pilot program set for early spring.

“It will also show that the vast majority of the men and women of the Chicago Department do the job correctly. I think that’s what the cameras will show,” Escalante says.