In the wake of the grand jury’s failure to indict Officer Darren Wilson for the death of unarmed teenager Michael Brown—and in light of conflicting eyewitness accounts of the incident—many have argued that video evidence would have helped a lot. Body-mounted cameras offer a technological solution to what is otherwise a problem of human moral complexity: eyewitnesses can’t agree; officers can’t behave; human evidence can’t be trusted. Technology, the argument suggests, can supersede all of this. And then, of course, a grand jury in New York City failed to indict Officer Daniel Pantaleo in the death of another unarmed black man, Eric Garner.