My undergrad advisor and good friend Kent Sandstrom had a mantra which pretty perfectly encapsulates all of sociology: social problems require social solutions.
This simple phrase gets at the heart of why things like "sensitivity training" or "intercultural communication training" or all the other various effects to combat institutional racism in the workplace have typically failed -- because they treat a social problem (systemic racism) as an individual problem (people as discrete units either being racist or not). In fact, this phrase more-or-less argues that no such program will ever make a meaningful difference, as they will leave untouched the social foundations of racism, causing it to simply adapt to new parameters (witness the rise of "colorblind" racism).
Unfortunately, the calls for the use of body cams by police officers falls into this same trap of attempting to solve a social/institutional matter by treating it as an individual failing. And sure, in a very technical sense, racial disparities in our criminal justice system are initiated by individuals, but the notion that the rampant murder of Black Americans at the hands of the police is just a coincidental result of selected bad apples acting improperly is so laughably simplistic I'll leave Lord Google to explain it to you if you're having trouble grasping it.
The increasingly wide-spread call for body cams falls under the umbrella of the delightful term coined by Ronald Corbett and Gary T. Marx in this paper from a few decades ago. In it (and hey, I managed to find a free link, so you can just go actually read it, which is fairly rare for academic publishing, but that's another rant for another day) they decry what they see as the "technofallacy" of the police world. Actually, they note 10 separate technofallacies (seriously, go read the paper. It's eerie how prescient it is for being nearly 30 years old now). The very basic essence of the paper is that we can't technologize away social problems, no matter how good the technology seems to be.
More specifically, they're simply demonstrating the fallacy with the logic, long employed in basically every call for changes in policing, that this new form of technology will solve the problems we're having. As they note, new technologies, once thought panaceas to previous problems, often bring an entirely new set of unanticipated problems (in the case of body cams, one could note they will drastically increase the surveillance of Black Americans, which seems like a particularly Orwellian way to supposedly help someone).
But the central problem I have with the call for body cams is that they do nothing to address social conceptions of Blackness as inherently criminal, nor change unjustly crafted laws which specifically target the poor and communities of color. In other words, much like sensitivity training, body cams may make police incrementally less violent (though are by no means assured to do so), but they'll still being enforcing racially unjust laws.
Not to mention the fact that body cams will do nothing to change the culture of police specifically or the wider cultural assumption that police are acting in good faith and their word should be as good (or more likely, better) than the word or video of any citizen. Look at how before clear video evidence surfaced, police, local media, and much of the local population were more than happy to accept the officer's unbelievable (and empirically false) version of events in South Carolina. And as the Onion so perfectly points out, it's basically dumb luck such good video exists and we shouldn't experience much comfort that basic justice proceedings were only initiated after such unlikely video surfaced.
A nicely-sourced summation of many of the arguments against body cams can be found here (seriously, it's a great piece, go read it). As that piece notes, body cams were originally designed to exonerate officers, and are still much more likely to be used to help an officer than to punish them for bad behavior. For one, much like the Obama White House will gladly leak info making it look good while doggedly pursuing prosecution against leaks that make it look bad, police officials across the nation have been happy to share body cam footage when it exonerates officers, but claim the footage can't be released or doesn't exist when it conflicts with the official version of events.
For an especially glaring example of this, the New Orleans PD recently instituted the use of body cams. In 145 incidents of violent behavior committed by police wearing body cams, only 49 have footage available, meaning that in the majority of such situations, the cameras were either not on in the first place, or the footage just happened to disappear after the incident.
Of course, none of this is to mention that no one is happier about the increasing demands for police to wear body cams than the Taser corporation, maker of the AXON body cam, the most popular model of body cams for police. Granted, a broken clock can be right twice a day, but I'm always going to be a little hesitant to support anything that makes a weapons manufacturer salivate.
Here I need to preemptively argue against Corbett and Marx' 10th technofallacy that by arguing against the means I may be misperceived as arguing against the ends. Obviously, I want a solution to our horrid racial injustices in the criminal justice system (and elsewhere) as much as the next person.
But that's actually why I'm concerned about the major push toward body cams; because not only are they incapable of solving the problem (or, I would argue, making a significant difference), but they sure seem like a good idea. And the danger of something that sounds so intuitively effective but which does actually not work is that it will allow people to forget about the problem. The sudden rise in discussions of police violence and racism dominating so much media is not because the problem has gotten especially bad recently, but because for a complex mix of reasons, white America is finally paying attention to these issues (Black Americans did not need Michael Brown or Eric Garner to show them that police violence is highly racialized). With the institution of a simple and attractive (yet ineffective) solution such as body cams, I fear (and history largely backs me up on this), that a large chunk of these folks who have just discovered police brutality and racism will now consider the matter solved, and move on to other things.
And then we'll be back to where we were before, except now our cities will be spending even more of their limited budgets on more fancy tech for the police, while slashing budgets elsewhere to pay for these toys. Which is an almost inevitable outcome of attempting to solve a social problem through individual means. So until and unless body cams are considered only a small part of a much larger reshaping of our forces of social control, I'll remain wary about calling for their use.