S.C. Code § 58-13-910
Upon the application of the superintendent or manager of a railway or other common carrier doing business in this State, the Governor shall certify special officers or constables for the protection and safety of all property and interest of the common carrier, if the officers and constables are paid by the common carrier applying for their certification. Special officers or constables appointed pursuant to the laws of another state for protection of interstate shipments, passengers, and employees of railroad companies commissioned as railroad police officers in another state in which the common carrier operates and who meet all law enforcement training standards required in this State must be certified under the doctrine of full faith and credit with capacity in this State to enforce the laws for the protection of interstate shipments, passengers, and employees of railroad companies. The capacity may not be interpreted as a state commission but exists by virtue of the State of South Carolina under the doctrine of full faith and credit recognizing and giving full force and effect under our laws to the legal capacity created in the complying state.
S.C. Code § 58-13-910