What risks and objections count against police body cams?

Switching the camera on late can escalate a situation; officers who see the camera as a sign of mistrust may work less well; the recordings can expose officers or citizens to humiliation, blackmail or retaliation; officers may avoid necessary force; and the money might do more good elsewhere.

• Escalation: studies found more assaults in some cases. One explanation is that officers switch the camera on only once an encounter is already heated, and the person sees that as a provocation.
• Mistrust and motivation: if officers see the camera as a tool of control, a sign of mistrust and a risk to their career, their dissatisfaction is likely to lower their overall efficiency.
• Data misuse: the most obvious harm. Recordings can expose officers or citizens to humiliation, blackmail and retaliation.
• Chilling effect on necessary force: an officer may hold back even where force would be justified, for fear it will look excessive on video and lead to discipline.
• Opportunity cost: the money spent on body cams could almost certainly do more good elsewhere, for example against disease or poverty in low-income countries. This is a typical utilitarian objection: compare the good a measure does with the good the same resources could do elsewhere.

Go deeper:

• Wikipedia: Body camera — research findings and privacy concerns.