I assume you mean police officer.
The short answer is "Don't". You will only become sadder and madder when nothing gets done. Or frightened when something is done - to you.
But if we assume that you have a hospital report and reputable witnesses (upper middle class, no priors, property tax payers) and/or a camcorder with Rodney King-ish footage in it, then you would report it to the governing authority of the police (usually the town council/Mayor) and the District Attorney and the Chief of Police.
Needless to say, keep a copy of the tape in a friend's safety deposit box. (And tell a local reporter what you are doing, every step of the way.)
Also, retain a great attorney. And make sure that you are legally untouchable - the bag of pot in your drawer, your kid's habit of having underage friends over to drink, the building code violation on your garage - all these things need to stop/be corrected.
Drive safely, after you make the report. Full and complete stop at stop signs, no speeding, make sure you've a camcorder or cell phone with you at all times.
Finally, make your demands moderate. Go for the money, not for the officer being punished, and definitely not higher ups being punished. After all, if you win money, it won't be them that pay you, they'll just bill the taxpayers. But if you succeed in getting one of them punished, well, that's personal, and hurts them, so you'd probably need to move.
(If any think that the above is dramatic, please remember every movie you have seen about the good person wronged, who fights the good fight against the system and wins. Remember all half a dozen or so of them? Now guess what happened to the millions of others who had no movies made of them. That's right, there is a reason why those who win against the system are in the news - it's because it's news.)
Contact the police.
The possessive form of the noun police officer is police officer's.Example: The police officer's car blocked the escape of the suspect.
Yes, a police officer can issue a ticket to another police officer if they witness a violation of the law by that officer. Police officers are expected to uphold the law regardless of their own profession.
Police Officers
A police officer
corporal police officer is the first rank of the police department.
is the city police officer a state employee no
Ma'am
The police officer does not own the police car, the jurisdiction he works for owns it, and yes a uniformed officer can drive an unmarked vehicle.
A peace officer is another term for police officer. A police officer is someone who is paid to protect and serve the people.
The term is usually used to mean a person who is not a police officer that regularly gives information about crimes to the police.
It stands for criminal investigating police officer.