In Utah a person is guilty of a DUI if he or she controls a motor vehicle while having a breath alcohol concentration of .08 grams or greater or while under the influence of a substance to such an extent that he/she is incapable of safely operating the vehicle. A defendant can be guilty of a DUI in Utah even if he/she never actually drove a vehicle since "control" of a vehicle has been interpreted as meaning only that a defendant was readily capable of driving a vehicle. Accordingly, police and prosecutors may charge a defendant who is sitting in a parked vehicle with the car keys in his/her pocket.
DUI charges also implicate a defendant's Constitutional rights against illegal searches and seizures. Police must have a legally permissible reason for stopping a DUI suspect. Once stopped, police must have reasonable suspicion to believe that a defendant is intoxicated before police may conduct field sobriety tests. Further, a defendant must have failed at least one field sobriety test before her/she may Constitutionally be arrested for a DUI.
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