I work in forensics and am no stranger to the kind of patient you are describing. Unfortunately you should be very disturbed both at who is let out, and who is kept for a long time, our legal system is far from perfect.
Glad RNs are filing incident reports and officers are filing reports at prison. Documentation is critical in these sorts of situations.
Is there a behavior plan in place for the patient? If not, get one ASAP.
Staff NEED to be setting boundaries with this patient, if there are no interventions in place, the patient is controlling everything and you have a very, very messy situation on your hands.
IDT/leadership need to be looking at taking a hard look at resources, interventions, instituting behavior plans, and modification or restriction of privileges, if not modification and restriction of rights (e.g. mail is a right, however staff may need patient to open contents in front of staff, inventory, and have contents locked away if they are contraband for setting).
This is a tough place you are in and I sincerely hope it gets better for you soon.