Police brutality, what can i do to show i was innocent?

Ok i was working at a club as a bouncer, and the club was about to close, and i was standing at the door, to make sure people wont leave the club with no drinks, and i was talking to one guy, and i was facing inside the club, and a police officer ran into me trying to get in, but i did not see him and he never make sure that i saw him, so i block the way, and did not let him get in, and when i realize it was a police officer it was to late, and i got arrested, and i m gonna go to trial, but nobody want to testify for me, they are all scared, please what should i do, is there anyway i can prove i did not see him?