What are the legal consequenses?

A good friend of mine got caught with a small bit of marijuana today in Southwestern Arizona. He was handcuffed and sat in a cruiser but after a bit the police officer uncuffed him. He said that he already wrote “it” up and he would have a court date. He said a bunch a threatening things about what my friend would face. My friend is on disability from being hit by a car badly and so doesn’t have much money but also would be traumatized in jail due to his numerous physical and pyschiatric conditions. I was wondering what he might be facing. I have heard of other people with worse charges that got off completely when they had an attorney and if it would be worth it. Also did he really get arrested since he wasn’t booked or is it just a citation? Thank goodness I’m not that familiar with this kind of thing nut I would appreciate any help that I can give to him.