If a police officer makes a traffic stop of a vehicle, he or she may generally contact the passengers as well as the driver. If in doing so, he or she notices the passenger appears to have been drinking, and the passenger appears to be under 21 years of age, the officer may investigate that as as an underage consumption of alcohol case. Part of the investigation would be asking the person to show identification to determine if the passenger is under 21. The officer can request an intoxilyzer test be taken if the passenger is in fact under 21.

If the officer cites the passenger for underage consumption of alcohol, and if the person is found guilty, the person could receive anything up to the maximum that is available for a class one misdemeanor. In an adult court setting, that includes jail of up to six months, possible probation for up to 3 years, and / or fines of up to $2500. Most courts set a fine of about $250 for a first offense.

If the case is handled in juvenile court, possible penalties range from merely a fine to probation or incarceration up to the minor's 18th birthday. On a second offense in juvenile court, the judge must order MVD to suspend the Minor's driver's license until the Minor's 18th birthday. (A.R.S. § 28-3320).