you can not assault a police officer. Period.
Even if they are crooks. I got caught up in an extortion scheme in the Philippines, which involved a local cop and a bar owner. The cop had stopped me in the bar and taken my military ID. He knew I would get an automatic 30 day restriction to the base if I lost it, and the bar owner was going to claim I assaulted him unless I paid them off. So I did and got my ID back. Sometimes you just can't win and need to be smart enough to know it. I could have easily found myself in the Olongapo City jail, and then in trouble with my command, and none of them would have listened if I said the cop was crooked. I learned a lesson and was more choosy about where I drank after that.