S.C. Code Ann. § 44-52-150

If any patient involuntarily committed to a treatment facility is absent without permission a law enforcement officer may, upon written order of the head of the treatment facility and without the necessity of a warrant or court order, take the patient into custody and return him to the facility. No person may be reconfined pursuant to this section after being continuously absent from the jurisdiction of the Office of Mental Health for at least one year.