Any given health care provider (e.g. doctor, clinic, practice, etc.) may make it's own decisions as to whom they want to take as a patient, and can base those decisions on their medical judgment as the risk that a patient poses, to him/herself or to others, based on the patient's medical and criminal history. If the pain management provider/practice/group feels that your substance abuse and criminal records make you an inappropriate or potentially risky patient for them, they have the right to decline to treat you.