The Bloomberg editorial staff says no:
Videos often lack critical context, and studies have repeatedly shown that jurors can be misled by variables such as a film’s angle or focus, which can unduly sway perceptions of guilt. That cuts both ways: Footage of a protester bumping into a cop, devoid of context, could make life much easier on a prosecutor.
Police cameras are also prone to intentional abuse. With mysterious frequency, they seem to accidentally get switched off or malfunction at critical moments. One obvious remedy is to require that cops always keep them on. But that can be counterproductive. Witnesses and victims may be less forthcoming on camera. Attracting competent officers could become harder if their every interaction is recorded. Crucially, officers may simply avoid engaging certain communities, or avoid areas where confrontations are likely, if they know they’re being filmed.
Finally, equipping police with cameras and audio recorders means that they’re constantly conducting surveillance on innocent civilians — and potentially storing it all. Police frequently enter private homes and encounter people in medical emergencies who may not want to be filmed. Some officers may be tempted to record people on the basis of race or religion. And some departments have asserted that the public has no right to see such footage.
In short, a policy intended to empower the public and monitor the police could have precisely the opposite effect.