Security footage showed a dark sedan turning a corner and accelerating onto the boardwalk, mowing down the unsuspecting crowd.
Another camera appears to show the speeding car swerve into pedestrians as they dive out of the way.
Snapchat, which is located on the Venice Beach boardwalk, captured these images of the car swerving into people.
Terrified witnesses gathered after the incident as police and firefighters attended to the injured.
Video captured in the aftermath showed a chaotic scene, with injured people on the ground.
"There was people kind of stumbling around, blood dripping down their legs looking confused not knowing what had happened, people screaming," witness Louisa Hodge told the AP.
Authorities said late Saturday that a person of interest was being questioned in connection with the hit-and-run and that the Dodge Avenger had been found in nearby Santa Monica. A motive for the incident was still undetermined.
One woman was killed and 11 others injured.