There has been a substantial drop in the number of complaints from members of the public against the police when law enforcement officers are deployed with body cameras.
According to a study at Cambridge University, which researched police officers working over 4,000 shifts in seven districts across California and the UK between 2014-15, there were 93 percent fewer complaints lodged by the public than in the 12 months leading up to the trial. A similar year-long exercise in 2013 carried out in Rialto, California, registered a drop of 87 percent in the number of complaints from civilians.
Growing use of body cameras
The use of a body worn camera increased after several incidents involving US police fatally shooting unarmed civilians, which were filmed by members of the public. President Obama backed a call for federal funds to be made available to police forces who wanted to purchase body cameras for their officers.
In the UK, there was a call for the Metropolitan Police in London to wear body cameras when they carried out stop-and-search operations after persistent complaints alleged that ethnic minorities were disproportionately targeted.
The move has generally been welcomed as it increases police accountability and leads to more transparency, though critics have expressed concern that guidelines make it easy for the footage to be tampered with and that the devices might be a tool for ever broader surveillance.
There are best-practice guidelines established in the UK http://www.pinnacleresponse.com/body-cameras-and-the-law/ but there is no common legacy across the different states of America. Sceptics maintain the effectiveness of body worn cameras will only be determined when there are strict policies to govern them.
Changing the culture of policing
While a body worn camera can provide evidence of police misconduct or an inappropriate response, it can also protect them against malicious allegations.
All studies have suggested that when officers do wear body cameras, the public not only feels safer, but they are less likely to escalate the situation so it turns violent. This is particularly true when the officer has made it clear that the body camera is recording.
Dr Barak Ariel of the Institute of Criminology at Cambridge says the wearing of body cameras has changed the behaviour of police officers. It makes them more aware of how they should conduct themselves while on duty, he says.