I just wanted to let you know that I broke my right arm a couple of weeks ago so some of my answers may be shorter than normal, but still complete, and there may be typos or other small issues. I have to spend less time than normal on the computer and it also takes me a little longer to hunt-and-peck using just my left hand so please bear with me. I am trying alternates to typing, such as a voice recognition system, but it has a steep learning curve.
Please be patient because at any point it may take a while to do research or type my answer/response. In addition I have to leave for physical therapy soon but will be back this afternoon.
You could file with the court to "emancipate" him but realistically it would be very hard to get that done and get a hearing within the next 78 days.
What you may want to do instead is go and hire a local lawyer to visit with the authorities on your behalf and see if they can jail him pending his second charge or possibly even get him committed to a drug rehab facility. Then, when he turns 18, you can evict him and ask the court to issue a protective order where he isn't allowed to come around you.
The cost to have a local lawyer speak with the authorities would be minimal although if he has to formally file for commitment or file the eviction there would be charges for all of that work.
If your question has been answered then I'd offer my best wishes to you and ask that you please not forget to leave a 5 Star Positive Rating so I receive credit for my work. Of course, please feel free to ask any follow-up questions in this thread. I want to be sure all of your questions are answered.