Does a police officer have an affirmative duty to arrest and charge a person?

7 Police officers do have affirmative duties. They must, without unnecessary delay, take the arrested person before a committing magistrate to be charged with the offense and have bail set as any unnecessary delay may amount to false imprisonment. (Vernon v. Plumas Lumber Co. (1925) 71 Cal.App. 112, 117, 234 P. 869.) There is also an affirmative duty placed on the district attorney. Once he or she has filed a complaint, it is his or her responsibility to gather and present such evidence as will both convict the guilty or exonerate the innocent. (Tribulski v. County of Los Angeles (1978) 83 Cal.App.3d 828, 831, 146 Cal.Rptr. 229.)