This is an interesting question that we get from clients and prospective clients during free consultations all the time. You got to  stop for a minute and remember - the criminal justice system has been prosecuting people and putting them in prison since pre-colonial times, and going back hundreds of years before that in England and other countries. We’ve only had body cameras in NH for the last couple decades. Their existence and use by some police departments doesn’t change the fact that people are convicted each and every day based solely on uncorroborated witness testimony - what the person says under oath that  they saw, heard, smelled, otherwise observed. 

The other interesting thing about this question is that body camera footage seems to help the defense more often than the prosecution. But it does take some of the “mystery and mystique” out of criminal defense. If the accused driver is filmed under oath saying things like “I’m sorry, I never should have been driving, I screwed up, I just ruined my life, I’m going to lose my job”, etc, it’s probably going to be a tough case, and there is no lawyer magic that can easily explain away those types of incriminating statements.