Recent events in the St. Louis suburb of Ferguson, Mo., are a stark reminder of what can happen when an interaction between a law enforcement officer and a civilian goes tragically awry.But the shooting death of unarmed teenager Michael Brown at the hands of a policeman might have been prevented — at the very least, the exact circumstances surrounding the incident that has incited an entire community would be more readily known and the controversy potentially subdued — if the officer involved had been wearing a camera.It’s not a novel idea. And Fort Worth, to its credit, may even be a bit ahead of the curve. In March, the City Council approved the purchase of 400 digital, body-mounted cameras for local police (on top of the 200 already in use), equipping more than one-third of the force with the devices.Big city police departments from Los Angeles to New Orleans — Dallas has 200 cameras on the way — are beginning to outfit officers with lapel or eyeglass cameras and microphones. According to the Wall Street Journal, the impact of body-mounted cameras, a mandatory accessory for cops in Rialto, Calif., is quite significant.The first year that the camera program was implemented in the Southern California city, the use of force by officers declined 60 percent and complaints against police fell 88 percent.Why? It’s psychology.The knowledge that every action they take is being recorded and therefore open to additional and repeated scrutiny motivates officers to be on their best behavior, improving transparency, accountability and ultimately increasing trust. The cameras affect civilians, too. The mere presence of recorded footage appears to reduce the number of people willing to contest the nature of police actions or falsely accuse an officer of misconduct. (And it should be noted that police cameras are much cheaper than body armor and tanks.) They are a useful and worthy tool, but certainly no substitute for other meaningful attempts to bridge the divide between police and civilians that exists in far too many American communities. To that end, there’s still a lot of work to be done.