S.C. Code § 44-17-870
If a patient involuntarily committed to a facility under the jurisdiction of the State Department of Mental Health is absent without proper authorization, a state or local law enforcement officer or employee of the department appointed pursuant to Section 44-11-70, upon the request of the facility superintendent or director or a designee and without the necessity of a warrant or a court order, may take the patient into custody and return the patient to a facility designated by the department. No person may be reconfined pursuant to this section after being continuously absent from the jurisdiction of the department for at least one year unless criminal charges are still pending against the patient or unless he was committed to a facility of the department pursuant to Chapter 24, Title 17.
S.C. Code § 44-17-870