Seattle police get body cams starting today

On Thursday, a dozen Seattle police officers strapped on body cameras for the first time.

By the end of 2017, 850 officers will be using them.

Seattle Police has been using cameras mounted on patrol car dashboards, but the department determined that wasn't enough. Because sometimes that footage just doesn't capture the moment.

Like in 2010, when a dashcam video released by Seattle Police showed the shooting of a Native American woodcarver. The death of that woodcarver, John T. Williams, roiled the city.

In the video there's the man with the knife, then the officer. Then they're gone. The shots heard are off-camera.

Police departments have invested in body cams for officers to show what really happens in these confrontations. But also, everyone acts differently when they know they're being recorded.

A year-long study by the University of Cambridge found that body cams reduced police use of force by more than half. Use of cameras reduced complaints against officers by more than that.

But police body cameras only work when officers turn them on. In Charlotte, North Carolina, and in Washington, D.C., this year, officers didn’t do that until after shooting.

There are also concerns about officers violating privacy by recording too much. Still, Seattle is joining other police departments across the country that have decided it is better to have the video than not.