17 December 2015, 19:27 GMT
In the video, the officer is seen grabbing a male demonstrator by the throat and throwing him into a wall. There is no indication that any provocation warranted the violent attack.
After the assault, officers crowd around the man, presumably to block camera access, and ordered the crowd to move back.
“See, the officers in Baltimore will continue to provoke protesters tonight, as they want confrontation,” civil rights activist Deray McKesson wrote of the incident.
— deray mckesson (@deray) December 16, 2015
Baltimore Mayor Stephanie Rawlings-Blake issued a statement the same evening saying that city officers are prepared to respond to violence in the wake of the announced mistrial of the first of six police officers charged in the death of an unarmed black man in custody.
After 16 hours of deliberations, the jury remained hung on the guilt of Officer William Porter, who was charged with involuntary manslaughter.
