What is the legal effect of an unlawful arrest or detention?

Rather, the legal effect of an unlawful arrest or detention is to merely remove the cloak of authority from the officer because the officer is not acting in the performance of his duties. As stated in People v. Curtis, supra, 70 Cal.2d at pages 355-356, 74 Cal.Rptr. 713, 450 P.2d 33, "We confirm that a resisting defendant commits a public offense; but if the arrest is ultimately determined factually to be unlawful, the defendant can be validly convicted only of simple assault or battery."

However, execution of an unlawful arrest or detention does not give license to an individual to strike or assault the officer unless excessive force is used or threatened; excessive force in that event triggers the individual's right of self-defense. (People v. Curtis, supra, 70 Cal.2d at pp. 355-357, 74 Cal.Rptr. 713, 450 P.2d 33.)