He will very likely be free to go; as soon as he identifies himself.
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He should go free even if he doesn’t identify himself.
Nope.
You see, Utah is one of 15 states that have a adopted the Stop and identify statutes.
In 13 states (Alabama, Delaware, Illinois, Kansas, Louisiana, Missouri, Nebraska, New Hampshire, New York, North Dakota, Rhode Island, Utah, Wisconsin), police may demand identifying information;
.... In states whose stop and identify laws do not directly impose penalties, a lawful arrest must be for violation of some other law, such as one to the effect of resisting, obstructing, or delaying a peace officer. For example, the Nevada stop and identify law challenged in Hiibel did not impose a penalty on a person who refused to comply, but the Justice Court of Union Township, Nevada, determined that Hiibels refusal to identify himself[24] constituted a violation of Nevadas obstructing law.[25] A similar conclusion regarding the interaction between Utahs stop and identify and obstructing laws was reached in Oliver v. Woods (10th Cir. 2000).
and finally
Whether an arrested person must identify herself may depend on the jurisdiction in which the arrest occurs. If a person is under arrest and police wish to question her, they are required to inform the person of her Fifth-Amendment right to remain silent by giving a Miranda warning. However, Miranda does not apply to biographical data necessary to complete booking.
Odds are that as soon as he cooperates, he is free to go. I suggest that if this is offensive to you, stay away from the 24 states that have enacted this sort of restriction. I'll give you a hint; it was likely brought about because of illegal immigration.