The fatal shooting of teenager Sammy Yatim by police on a streetcar near downtown Toronto's Trinity Bellwoods Park on the weekend has triggered outrage. The incident, captured on amateur video and posted online, has raised the issue of whether police should be recording their own video.

The shooting video has been viewed countless times online and in the media, and it leaves many questions about the decisions made by the officers involved.

But since none of the more than 20 officers at the scene were equipped with body-worn video cameras (BWV) — a technology more police forces are turning to — the public remains unaware of their perspective of the incident.

Video has been playing an increasing role in investigations of police activity. Video and policing first intersected in a big way in 1991, when George Holliday recorded Los Angeles police officers surrounding and beating Rodney King. Four of the officers were tried and acquitted.

In Canada video has played a part in a number of high-profile investigations, ranging from the death of Robert Dziekanski in 2007 after being shocked with a stun gun by RCMP officers, to the G8/G20 protests in Toronto in 2010, to the Vancouver Stanley Cup riots in 2011.

Friends, family and outraged citizens took part in a protest march on Monday evening, following the shooting of 18-year-old Sammy Yatim on a TTC streetcar two days earlier. (Steven D'Souza/CBC)

But much of this video has come from bystanders or security cameras located some distance from the event. So police forces around the world, including some in Canada, are starting to equip their officers with in-vehicle and body-worn cameras to get an audio-visual record of how events unfold from the point of view of officers.

BWV trials underway in Edmonton and Ontario

A number of companies are developing BWV technology for police, including Reveal Media in the U.K. and Seattle-based Vievu. Taser International Inc. makes a camera that police can mount on a pair of glasses.

Ottawa Police adopted a Taser model equipped with a video camera in 2009, but decided to discontinue its use in January this year because they found it gave them no added value, according to a spokeswoman with the force.

BWV cameras generally sell for $700 to $1,200 and are expected to go down in price, Brian Flippance, the president of Integrys, told CBC News. Integrys is a technology distributor that sells Reveal Media cameras in Canada.

Flippance and other experts have told CBC News that an argument in favour of BWV is that people behave differently when they know they are being videotaped, both the civilian and the officer. "It calms down the situation," Flippance says.

Police in Edmonton, Alta., and Amherstburg, Ont., are currently conducting BWV trials using the RS3-SX camera from Reveal Media. The RS3-SX is a self-contained unit with an LCD display of what the camera is recording that someone looking at the police officer can see.

The RS3-SX body worn video camera by Reveal Media is being used in trial studies in Edmonton, Alta. and Amherstburg, Ont. (Courtesy Integrys/Reveal Media)

Edmonton police are in the midst of a $450,000, three-year pilot project with BWV. Fifty officers are equipped with BWV and another six will get the equipment next month, Mary Stratton, the coordinator of the Body Worn Video Pilot Project, told CBC News. She notes that the hardware represents a small share of the overall costs.

The Edmonton Police Service wants "objective evidence of pros and cons and the costs and benefits of this kind of technology," she said.

Stratton highlights some of the issues with BWV: privacy, when to start recording in a dynamic situation, when to inform people you are recording, what situations are inappropriate to record.

The report on Edmonton's study is due by the end of 2014.

In Amherstburg, just one of the force's 20 police officers is equipped with BWV during the trial, and for just 30 days.

Police Chief Tim Berthiaume told the Windsor Star that BWV, "is one tool of being accountable and being open and being transparent."

Pros and cons of BWV

Paul Cook, the president of the Ontario Association of Chiefs of Police, explained the advantages and disadvantages to CBC News.

On the plus side is the video evidence that can be used in court, "the opportunity to protect officers from false allegations of misconduct, and also provide us with the opportunity to hold our officers accountable if there was misconduct," he said.

Cook, who's also the police chief in North Bay, said the big disadvantage is the cost of purchasing the technology and maintaining it. And police forces need to weigh BWV against other technology like mobile workstations in cruisers, in-vehicle video, using technology for traffic enforcement and so on.

He also noted concerns from a privacy standpoint and issues about securing and maintaining the recordings.

Fewer use-of-force incidents

A number of other trials have indicated that beyond just providing a record of events, BWV use by officers can have an impact on policing itself.

Victoria police conducted a study in 2009 that "greatly supports" BWV. In the end they did not acquire it, largely because of the cost, but videos recorded during the study became evidence in criminal cases, many of them leading to convictions — and almost all of them by way of a guilty plea.

The report filed at the end of the trial period states that "Public hostility/aggressiveness decreased" and "Public complaints were reduced to zero during the test period."

For the police officers, the video provided them with a more accurate account of the incident and improved the quality of the evidence they could submit, according to the report.

British and American research has also found an increase in arrests and charges, a reduction in public complaints and positive public response to BWV. The first pilot projects were conducted in the U.K. in 2005.

Perhaps the most highly regarded report is from Rialto, Calif., which found the number of use-of-force incidents was cut in half when officers used the cameras.

And the number of citizens' complaints during the trial was one-tenth what it was during the prior 12 months.

The cameras are now standard issue for police operations in the city of 100,000.

Police unions divided

Mike McCormack, head of the Toronto Police Association, told the Toronto Star in May that his union opposes BWV.

Toronto Police Association president Mike McCormack says his union opposes officers using body worn video. (Nathan Denette/Canadian Press)

"We don’t think it protects officers any more against complaints or protects the officers any more in gathering evidence in what they do," he said.

"I believe we have sufficient accountability," McCormack added.

In Ottawa, both the Defence Counsel Association and the local Police Association have come out in favour of BWV.

"Judicially we have become so much under attack that I think it's important to have our side explained," Matthew Skof, President of the Ottawa Police Association, told CBC News in 2012.

Inspector Steve Goodier of Hampshire Police in the U.K. told Police Oracle, a website used by every U.K. police force, that it's the officers who are asking for BWV.

"It is not something that has been pushed down. Officers are finding that the cameras protect them and help them with their job, which is why they are really willing to use them," the website quotes him.

And the U.K.'s Minister of State for Police, Damian Green, said in a July 9 speech that he wants to see more forces using BWV. "Evidence shows up to 90 per cent of suspects plead guilty when they see the recorded evidence," he said.

Another issue is who has access to the recordings. In the U.S., police unions have expressed concerns about their superiors' using the videos to monitor officers' daily routine or search for minor infractions.

For civilians, Seattle resident Eric Rachner's 2008 arrest may be instructive. He won a $60,000 lawsuit because the police were reluctant to turn over video shot from a squad car camera, video Rachner said would prove that he'd been the victim of an illegal arrest.

"They really don't want to give it out unless it is just a clear-cut example of something that supports what the officer said, or tends to show that the arrestee is guilty," Rachner told National Public Radio.