Any involuntary patient may apply to be transferred to voluntary status of hospitalization and shall be so transferred if he is able to understand and exercise the rights and powers of a voluntary patient unless the chief medical officer finds that this would not be in the best interest of the patient, which finding shall be entered in the patient's clinical record and signed by the chief medical officer. In any case in which such transfer to voluntary status occurs and in any case in which a patient transferred to voluntary status is discharged, notice of such transfer or discharge, as the case may be, shall be given: to the patient and his representatives; if the patient's hospitalization was ordered by the court, to the court which entered such order; if the patient was admitted to a facility under subsection (a) of Code Section 37-3-41, to the physician or psychologist executing the certificate; and, if the patient was under criminal charges, of which the facility received written notification, by certified mail or statutory overnight delivery to the law enforcement agency originally having custody of the patient. An involuntary patient transferred to voluntary status, which patient is under criminal charges, notice of which charges have been given in writing to the facility, may only be discharged into the physical custody of the law enforcement agency originally having custody of the patient. Such agency shall assume such custody within five days after the mailing of notification to the agency pursuant to this Code section.