The video shows two men walking across a street, and then running and shooting. Also clearly visible are flashes from the high-powered weapon.
The shooting happened about 7:40 p.m. Wednesday along Wilmington Avenue near 109th Street, about two blocks from the Watts Tower.
A 7-year-old boy was hit in the leg in the shooting, and is expected to be OK.
Police say officers were nearby and rushed in when they heard the shots. A massive police presence descended on the neighborhood after shots were fired.