Someone Illegally Dumped Using My Vehicle

So I was financing a vehicle for someone we had a verbal agreement they were responsible for maintenance and any car expenses (insurance , registration etc) thry dumped something from the vehicle the state have the license from them driving off and fined me around 100k.

I don't have that. I do have police reports when I reported it stolen because they didn't want to return it (found out they had tons of parking tickets they ignored) a receipt of police returning the vehicle to me with then listed as driver. Months of text conversations arranging payment them agreeing to pay back tickets and telling me how to get on a payment plan. I have a copy of the business they setup that deals with dumping materials.

I'm going to ve going against an attorney representing the state on my own. What shouldn't I say or what steps to take?

Do I outright say I'm not responsible he was driving ? Do I need to attempt to notify him of the hearing? (He essentially went no contact after making a few threats if I didn't return the money he already paid on the vehicle so all the tickets and stuff I'm left on the hook for)

I don't have a license and don't drive and have been posting the vehicle online to find a buyer (should I include that?)