I too, am curious as to what OP means when he says he wishes to complain because he doesn't like how his event was handled and that the police acted poorly. Is he alleging actual misconduct on the part of the police or merely expressing a philosophical disagreement as to how they went about their jobs?

To the OP (and FWIW): 10 people can witness a police activity and give you 10 different opinions as to how they think things could have been handled better. That doesn't mean the police acted improperly. Disciplinary action is not taken against them simply because a member of the public is unhappy with what they did. Only when the police violate the law, or department rules, policy, directives, or the instructions of a superior are they liable for punishment.