Should the fines be taken care of out of these earnings?

My son was picked up at a friend's house and charged with Obstruction of Justice for telling the police he didn't know if the friend was home or not. He's been incarcerated since then due to a violation of Drug Court, etc. He has been in ODOC custody the whole time. His release could be, as soon as, the first of August. At the time he got the ticket he and I both knew he was going to prison so he asked me to contact the police that issued the ticket to inform them of this. Over a period of 1 month, I called this small town police department a total of 14 times. Many times having to leave a message, but several times I spoke with the lady who answers the phone. Each time, I went through the whole story and each time I was told someone would call me back and let me know something. Never happened. I was even trying to set up payments for this ticket and could not get any assistance at all. Yesterday in the mail, my son received a notice from The Warrant Division. It says there is a criminal warrant and if they don't hear from him or receive $896 in (10) days, they will proceed in suspending his driver's license. I'm in no position to pay this amount of money and I don't even know how much the ticket was to begin with. I have no reason to think I can find anything out by calling them either. This incarceration stems from a 2008 charge and he has been in and out of trouble since then. He's even completed a drug court program once. He is currently in an ODOC Halfway House and employed. I was told that this facility controls his earnings and that a portion goes into a "fees & fines" fund. Should there be a warrant issued considering the situation? How should I proceed based on this information? I rarely speak with my son and am not sure when I'll talk to him again.