The footage shows how the traffic stop escalated quickly.
The footage shows how the traffic stop escalated quickly. YouTube/Texas Department of Public Safety

From the New York Times:

A dashboard camera video taken by law officers released Tuesday showed in excruciating detail how a routine traffic stop led to a woman being dragged from her car and arrested, three days before she was found hanging in her jail cell.

State legislators who saw the video just before it was released publicly sharply condemned the officer’s behavior, which the director of the Texas Department of Public Safety, Steven McCraw, said was a violation of department arrest procedures. State Senator Royce West, Democrat of Dallas, said the woman, Sandra Bland, 28, should never have been taken into custody.

State Representative Helen Giddings, Democrat of Dallas, said, “This young woman should be alive today.”