In the wake of President Obama’s recent proposal to spend $263 million of federal funds to purchase 50,000 body cameras, a study from the University of Cambridge’s Institute of Criminology has shown that officers with body-worn cameras are significantly less likely to use force.

The study was conducted by Dr Barak Ariel, Dr Alex Sutherland, and William Farrar, chief of police in Rialto, California, over a 12-month period from February 2012. Police officers in Rialto were randomly assigned body cameras during shifts.

The new study was conducted at Cambridge's Institute of CriminologyAlasdair Massie

During the experimental period, there were eight uses of force by officers wearing body cameras, compared to 17 by those not wearing them. This represents a 58.3 per cent decrease in the total number of incidents from 2011, when there were 67 reported uses of force. The total number of citizen complaints also fell, from 24 in 2011 to three in 2012. However, two of the three complaints were filed against officers wearing cameras.

The researchers hypothesise that mobile cameras produce a “self-awareness effect” that deters both officers and suspects from reacting with excessively aggressive behaviour.

Dr Ariel said: “An officer is obliged to issue a warning from the start that an encounter is being filmed, impacting the psyche of all involved by conveying a straightforward, pragmatic message: we are all being watched, videotaped and expected to follow the rules.”

The research indicates that body-worn cameras are especially effective relative to alternatives such as CCTV, as there is greater certainty that an encounter will be adequately recorded. 

The US government estimates the cost of installing body cameras at up to $900 each. There are also additional costs incurred in user licenses, storage space, security, and maintenance. Nevertheless, reductions in litigation and other benefits have the potential to offset these costs, and analysis of the Rialto data suggests that every dollar spent produced four dollars in savings.

The study cautioned that more electronic surveillance might lead to increased digitised tagging of individuals and encroachments on personal rights. The value of officer testimonies in court could also be undermined, affecting police credibility in unrecorded cases.

Dr Ariel and his colleagues are currently replicating the Rialto experiment with over 30 police forces around the world, including the Police Service of Northern Ireland (PSNI). Early signs are supportive of the findings in Rialto, though Dr Sutherland said “Rialto is but one experiment; before this policy is considered more widely, police forces, governments and researchers should invest further time and effort in replicating these findings.”

London’s Metropolitan Police is already piloting body cameras, with 1,000 cameras deployed at present. New York City has followed suit, with 54 officers wearing cameras beginning last month.