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Do body-worn cameras discourage undesirable behaviour?

NZ Security Magazine, Dec 2017 / Jan 2018

We look at two major studies of the behavioural impact of body-worn cameras.We look at two major studies of the behavioural impact of body-worn cameras.


Does the deployment of body-worn cameras actually reduce the threat of aggressive behavior towards guards and frontline enforcement staff? We take a look at two key studies providing an international and a local perspective.


Cambridge-RAND trials

Claiming to be one of the largest randomised-controlled trials in criminal justice history, the University of Cambridge and RAND Europe conducted ten trials throughout 2015/14 looking at body-worn cameras' use in law enforcement.

This research, led by Dr Barak Ariel at the University of Cambridge, encompassed eight UK and US police forces, 2,122 participating officers, a total population of two million citizens, and covered two million hours across 4,264 shifts.

Focusing on assaults against officers, use-of-force by officers and complaints against police by the public, the research threw up what were widely regarded as surprising results.

In particular, the study found that rates of assault against officers during arrest were 15 percent higher when BWCs were being deployed, compared to shifts where they were not. The research team offered two plausible explanations for this.

According to Alex Sutherland, Research Leader at RAND Europe, “there is an argument that the video monitoring might make police officers less assertive and more vulnerable to assault, meaning that the actual rate of assaults increases.”

At the same time, notes Sutherland, “police officers might feel more able and equipped to report assaults against them once they are captured on camera, even if the officer does not sustain visible injuries.” According to this explanation, the footage may give officers evidence-based confidence to report assaults that they would have otherwise lacked.

The Cambridge-RAND study appeared to ring true in the case of Christchurch City Council, which noted that the number of assaults and abuse being reported by its parking wardens had increased in the past 12 months despite them being issued BWCs in April 2016.

The council’s transport operations manager Aaron Haymes told New Zealand Herald that the BWCs encouraged staff to report incidents more due to the footage providing reliable evidence. “This means it's more likely that somebody will be held to account for their actions, and that encourages staff to report.

“Our experience has shown that the body worn cameras have increased safety for our staff by lessening the seriousness of incidents and discouraging undesirable behaviour,” he said.

Interestingly, the Cambridge-RAND study also found that if officers turned cameras on and off during their shift then use-of-force increased, whereas if cameras were kept rolling throughout a shift, use-of-force decreased.

“If an officer decides to announce mid-interaction they are beginning to film, for example, that could provoke a reaction that results in use-of-force,” Principal Investigator Barak Ariel said.

On the contrary, continued filming that is declared early to the filmed party resulted in more desirable behavioural outcomes. “The combination of the camera plus the early warning creates awareness that the encounter is being filmed, modifying the behaviour of all involved,” said Ariel.


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NZ Corrections Department pilot

In November 2012, the Corrections Department embarked upon a programme to improve issues affecting staff safety. The chief executive appointed an Expert Advisory Panel to investigate staff safety and advise on potential solutions, resulting in a piloting of BWCs.

According to authors of a summary of the pilot titled On body cameras in prison, NZ Corrections Chief Custodial Officer Neil Beales and Manager Operations Support Leigh Marsh, an issue considered by the Panel was how to reduce confrontation between two parties escalating into verbal and physical assaults within the high-tension context of the custodial environment.

“In their initial report, wrote Beales and Marsh, “the Panel indicated that the use of overt recording devices during incidents of escalating conflict could potentially significantly reduce the severity of such incidents, and the likelihood of the situation escalating further.”

A trial designed to test this theory using BWCs was staged over a six-month period in 2014 in two locations: a high security unit at Rimutaka Prison and a maximum-security unit at Auckland Prison. Around 30 staff and over 300 prisoners were involved, producing 26 hours of recorded footage across 157 events (where an officer activated their camera for safety or evidential reasons).

Trial feedback from both officers and prisoners indicated there was an increase in actual and perceived personal safety. “The trial produced some evidence to suggest that when custodial officers are equipped with BWCs there are reductions in frequency and intensity of assaults, and fewer occasions when physical force is used to resolve incidents,” Beales and Marsh wrote.

The trial recorded no serious assaults, five non-serious/non-injury assaults, and nine events where the prisoner “either de-escalated in the presence of the camera or clearly stated they would have struck the officer if the camera was not there.”

According to Beales and Marsh, analysis of all incidents over 12 months prior to the trial and during the six months of the trial demonstrated an overall reduction of incidents of between 15 and 20 percent. The analysis also demonstrated a reduction in the severity of incidents.

“The presence of these alone has helped draw a positive outcome to most incidents that may have before escalated further,” said one officer in feedback on the trial.

“Prisoners think twice about acting in an aggressive manner around staff whether it be to staff or another prisoner, also it has been said by prisoners that it can reassure them too,” said one officer. Since the cameras came into our unit I have not had a single negative comment from prisoners. If we remain professional at our job we have nothing to worry about.”

According to Beales and Marsh, analysis of the trial results identified the following high-level findings:

  • The frequency and intensity of assault events is reduced and the likelihood of physical force being required to resolve incidents is reduced
  • The presence of the cameras has a calming effect on the wider unit
  • Staff feel safer and more confident when equipped with a BWC
  • A feeling of ownership of the camera has a positive effect on uptake by officers
  • Camera footage has supported internal misconducts and external prosecutions
  • The cameras have provided officer training and development opportunities
  • The cameras have provided prisoner coaching opportunities where footage has been used to challenge prisoner behaviour
  • The cameras’ effectiveness to modify behaviour is dependent on how they are applied
  • The cameras keep officers professionally safe (preventing false accusations and complaints)
  • Costs associated with injuries sustained by staff when managing prisoners are reduced.

The findings of the trial were accepted by the Corrections Executive Leadership Team and a decision made to proceed to a wider roll-out of BWCs in high-risk areas. The Reveal system provided by New Zealand distributor CERT was ultimately selected by Corrections.


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