PHOTOGRAPHER ASAULTED BY POLICE OFFICER: legal help please!

Today, at the march at the Westwood Federal Building, while I was taking photographs for the LA Indymedia website, I was assaulted by a police officer. His name is Mulberry, badge number 15514 (see photos below). I noticed him attacking protestors at the front of the group and moved in to photograph what he was doing, and also him. When I turned my camera on him (to document his face, badge number, and name), he assaulted me. He first hit me with the tip of his baton in the middle of my chest, just below my collar bones. He then proceeded to strike me at least two more times, injuring my arm and my right leg/buttock area. The last time he struck me I had my back to him and was attempting to move away as quickly as possible. I have photos of my injuries, two eyewitnesses, and possible video footage, and would like legal representation to file charges against him. CBS has (and aired at least twice) footage of the assault on their news broadcasts. They have refused to give me a copy of the footage without a subpoena. If anyone has footage of the whole incident, I would greatly appreciate getting a copy. Thanks for your help, and for the support folks gave me throughout the rest of the day.