#BBCTrending: Capturing police on camera

A mobile phone recorded of the death of Eric Garner, a Staten Island man, after NYPD officers put him in what appears to be an illegal chokehold.

That video received hundreds of thousands of views. It lead to dozens of articles, tens thousands of signatures on online petitions, and a larger conversation about police techniques.

It was one of multiple videos of altercations with police, taken with a mobile phone and posted online. What these videos lack in quality and context they make up for in powerful imagery and, thanks to Twitter and Facebook, a giant audience.

Last month, police in Brooklyn, New York, were captured on film as they threw a pregnant woman to the ground, belly down. That video received hundreds of thousands of views.

Capturing police on camera is nothing new - the 1992 Los Angeles riots were spurred by video of police beating Rodney King. But as camera phones and social media become more ever-present, filming the police has become a tool for activists and those worried about police brutality. 'Copwatch' organisations across the country train civilians to use their phones to monitor police.

Dennis Flores, the founder of El Grito of Sunset Park, a copwatch organisation from Brooklyn, got the footage of the pregnant woman's arrest on 20 September.

He says his group has been documenting police brutality for 15 years, with an aim for greater accountability. The prevalence of smart phones has made it easy to organise his volunteers and provide better coverage.

Police departments have also been ramping up the use of body cameras to both provide greater accountability and to capture their own versions of disputed situations.

After police shot and killed 18-year-old Michael Brown on 9 August, officers in Ferguson, Missouri, adopted the cameras. The department joins 5,000 other departments nationwide.

The Wall Street Journal reports that a study released in mid-September found police with the cameras saw a 60% reduction in the use of force by officers, and an 88% cut in citizen complaints.

Filmed and edited by Anna Bressanin

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