<P> In the United States, interactions between police and citizens fall into three general categories: consensual ("contact" or "conversation"), detention (often called a Terry stop, after Terry v. Ohio, 392 U.S. 1 (1968)), or arrest . "Stop and identify" laws pertain to detentions . </P> <P> Different obligations apply to drivers of motor vehicles, who generally are required by state vehicle codes to present a driver's license to police upon request . </P> <P> At any time, police may approach a person and ask questions . The objective may simply be a friendly conversation; however, the police also may suspect involvement in a crime, but lack "specific and articulable facts" that would justify a detention or arrest, and hope to obtain these facts from the questioning . The person approached is not required to identify himself or answer any other questions, and may leave at any time . Police are not usually required to tell a person that he is free to decline to answer questions and go about his business; however, a person can usually determine whether the interaction is consensual by asking, "Am I free to go?" </P> <P> A person is detained when circumstances are such that a reasonable person would believe he is not free to leave . </P>

When are police allowed to ask for id