The theory upon which you need to develop a cause of action against the police is known as "false imprisonment."   False imprisonment has been defines as the "unlawful restrain of a person's freedom" or "act of restraining a person against his/her will in a bounded area without any justification."  False imprisonment generally refers to the confinement of a person without the consent of such person or without legal authority. The police have "legal authority" in a sense but no justification it appears from the way that you have written the facts. The time you were confined may or may not have a bearing here. I would indeed speak with an attorney in your area regarding the matter in detail. Good luck.