Axon (Vievu's parent company) told Engadget that it was partnering with the NYPD to address the situation. "We are working closely with the NYPD to investigate this issue," a spokesperson said. "The officer was not injured, however officer safety is of the utmost importance to Axon. We will do whatever is necessary to quickly and safely resolve this situation."

It's not certain whether or not there's a systemic problem with the cameras. While the NYPD suggests it might be, this could also be a one-off instance of battery damage -- a distinct possibility with any lithium-ion power pack. Either way, it's not what NYC's law enforcement wanted. The department intended to finish its body cam deployment by 2019, but it might have to push back that goal if it ends up replacing thousands of those units.