Police Body Cams: Not So Fast?

I’ve generally favored the idea of equipping police with body cams. But the ever wise Todd Zywicki of George Mason Law school offers the following caution about possible unintended consequences:

I think I am generally favorably inclined toward body cameras for police. But I also worry about the unintended consequences. For example, in a world of overcriminalization, often the best police judgment is to not enforce a law against someone. For example, you have the teenage kid pour out the beer instead of arresting him, throw away the marijuana instead of arresting him, or giving a speeding driver a warning instead of a ticket.

I worry that if the police are going to be forced to wear body cameras, then they are going to be more reluctant to exercise judgment and discretion in how they enforce these laws because they might later be second-guessed, especially if it later turns out that there is some disparate impact in policing. And I suspect that these instances of police exercising discretion to not enforce laws are far more prevalent than the rare instances where matters go awry. I also recognize that the costs of the latter situation are much larger. 

So while I think the benefits of body cameras probably outweigh the costs overall, I fear that one unintended consequence will be that there will actually be more arrests, especially of people who don’t really deserve it.

We already have lots of dash cam video, and audio recordings of officers interacting in their duties. I wonder if there have been any careful studies by criminologists of what data may have been generated from these existing monitoring systems.