This video from the Trayvon march in South Central on 11/14/13 (below) is not anomalistic in any sense in Los Angeles. If you look carefully at 0:27 you’ll see the cop hit the woman in the face. This kind of police violence is consistent.
Paramilitary, mass containment/suppression policing is how the LAPD does business in areas that have no viable financial infrastructure.
The LAPD opened fire with “less than lethal” projectiles two more times during the march.