I'm going to chime in here only because an Arizona attorney hasn't answered. I'm not a criminal law specialist, and only run into vehicular crimes as a personal injury attorney.
Your father was likely cited with A.R.S. 28-3480, which is operating a motor vehicle in violation of a drivers license restriction. That is a class 2 misdemeanor, meaning possible outcomes are 4 months jail-time, probation, and/or a 750.00 fine which will be more like $1,500.00 after all the surcharges. Even if your dad has a prior misdemeanor for the same behavior, the maximum jail time that could be prescribed should still be 6 months. There might also be restitution ordered for any property damage caused to the bus, which may (hopefully) or may not be paid by your dad's insurance.
The good news (in a way) is that if jail time is a potential outcome, and your father is indigent, a public defender could be assigned to help him. I'm not sure how it works specifically in Maricopa county, but usually the city prosecutor has to indicate if he intends to seek jail time so you and the court know whether this right could be triggered.
Likely, your father is a nice person with strong ties to the community. A prosecutor might be amenable to seeking only a fine for the Class 2 and perhaps restitution, though any of the above outcomes is certainly possible. With an attorney, you might be able to plea the class 2 down to a lesser offense, in exchange for relieving the prosecution of its burden to prove a case against your dad ("plea bargain").
As with any criminal case, your dad doesn't need to say anything to the prosecution, and should probably locate an attorney that can give him specific advice.
Hope that helps. Good luck.
This is printed in response to a general question, without knowing the specifics of your case. If you are in a eviction/detainer action, please disregard the above and see the Rules for Eviction Actions, using the same link posted above.
Hire an attorney to fight the ticket for a couple hundred dollars. It'd be worth the money.
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