Traffic Lights, Signs and Controls: How Do I Obtain Red-Light Camera Footage

This involves a traffic collision from the state of: California
Situation: Approx 1 week ago I was involved in a collision, non-injury, with a red light runner as I was making a left hand turn on a green arrow. An officer arrived on scene on a request for service. He took no report, no statements and no citations were issued. Reviewing the request for service report it does not mention me or my vehicle anywhere, only limited information of the other party. He did handle the exchange of information and I have the other parties info. He stated that there is red-light cameras (which there are) at the intersection. Now I am locked in a "he said - he said" situation with the other driver(through insurance co) over who is at fault. There were no witnesses but miraculously he produced a pedestrian (to his defense) who saw the whole incident but was not there or identified themselves to the Officer on scene.
My question is this; how do I obtain the red-light camera footage if no citation is issued? The PD is of no help. The insurance co, for whatever reason, is not actively pursuing the footage so I am left to my own to defend myself to keep my rates from increasing. How do I proceed?

Thanks!

Traffic Lights, Signs and Controls: How Do I Obtain Red-Light Camera Footage