Arizona’s new law compels law enforcement officers to make inquiry into the immigration status of a person who law enforcement has "reasonable suspicion . . . is an alien who is unlawfully present in the United States". Many on the radio and on the web suggest that this provision only applies when a law enforcement officer has lawfully stopped someone for suspicion of criminal activity or for a traffic violation. This is untrue.
The new statute presupposes a "lawful contact" between law enforcement and the person suspected of being an illegal alien. However, "lawful contact" between law enforcement and citizens includes police walking up to people in a public area and asking for identification. Florida v. Bostick, 501 U.S. 429 (1991); Florida v. Royer, 460 U.S. 491 (1983). However, the police may not demand identification and may not arrest for a refusal of a person to identify himself, unless reasonable suspicion exists that the person refusing to identify himself is engaged in some criminal act. Hiibel v. Humboldt County, 542 U.S. 127 (2004). So, while the police may not have probable cause to arrest the person detained for the crime he is suspected of committing, they can arrest the person, under most state laws, if the person refuses to identify himself, while being lawfully detained. In my experience, police understand that a verbal identification, which includes date of birth, is sufficient identification in most circumstances.
The genius [some would say evil genius] of the Arizona "stop and identify" law is that it creates a new crime under state law – illegal alien trespass. Thus, "lawful contact" is expanded to include all sorts of factors that did not amount to suspicion of a criminal conduct before the criminalization of illegal alien trespass. Thus, what would normally be considered profiling is transformed into reasonable suspicion of trespass. Lawful contact can now include detaining persons who appear to be Mexican and speak Spanish or speak English with a foreign accent. Once lawfully detained, law enforcement may require identification under threat of arrest.