Can I sue for false arrest in California?

Yes: an arrest without probable cause violates the Fourth Amendment and supports a claim under 42 U.S.C. § 1983, along with the state-law tort of false imprisonment. Unlike a malicious prosecution claim, a false arrest claim does not require showing that the charges ended in your favor.

Probable cause is the battlefield: an arrest is lawful if the facts known to the officer would lead a reasonable person to believe a crime was committed, and Penal Code section 847(b) shields an officer from civil liability when the arrest was lawful or the officer had reasonable cause to believe it was. Without probable cause, the arrestee holds a Fourth Amendment claim under 42 U.S.C. § 1983 plus state claims for false imprisonment and, where threats or coercion are involved, the Bane Act (Civil Code section 52.1). Timing is treacherous. The federal clock generally starts when the arrestee is held pursuant to legal process, arraignment, not when charges later end (Wallace v. Kato (2007) 549 U.S. 384), so the two-year period can run while a criminal case is still pending. State-law claims against the arresting agency require a government claim within six months (Government Code section 911.2). Damages cover the detention itself, lost work, and emotional distress.

Authority: 42 U.S.C. § 1983; Cal. Penal Code § 847