If your son is charged, you should get a lawyer for him as even a juvenile conviction can have long term consequences.

Your son merely being with someone else who shoplifts is not sufficient evidence to prove that your son was involved in the theft. The store may have such evidence or it may not. Very often loss prevention personnel simply make the assumption that two people together were cooperating in the theft even if they were not. I have the impression that this assumption is made even more often when minors are involved. A lawyer can conduct an adequate investigation and advise as to whether there is a serious risk of conviction or whether the charges can be contested. A lot may depend on whether a surveillance video exists and what it shows. A lawyer can probably follow local discovery procedures to obtain that in advance of any trial.

Also, a lawyer can advise as to whether there is a diversion or deferred sentencing program available to your son. If so, your son could avoid the risk of a trial and conviction by completing the program. This usually involves some counseling and/or anti-shoplifting classes, program fees, and perhaps some community service (although with a 12 year old I doubt community service would be imposed). After completing the program, the case is dismissed. I do not know if this is available in Ohio. Your lawyer can advise you about this.

I would also ask the lawyer about the civil demand letter. Usually, I advise people to pay it to get it over with. It is separate from the criminal process. However, in fact civil enforcement actions for the demands are rare. When there is a genuine issue of innocence, as there may be in your son's case, it may be best to contest that as well. I would defer to the opinion of your lawyer about that.