Can I sue the police if they arrest me without probable cause?
If an officer arrests you without probable cause, because the officer was mistaken about the facts that he thought supported probable cause, in most situations you will have a very hard suing the officer for damages. However, if the officer has made an unreasonable mistake, theoretically you could sue under 42 U.S.C. Section 1983, for violation of your Fourth Amendment civil rights.
In practice, however, civil rights suits tend to succeed only when the officer is a rogue operator, who abused the suspect in the course of an invalid arrest.
by: Sara J. Berman