S.C. Code Ann. § 23-24-30
Off-duty work performed by law enforcement officers shall not be considered as work done within the scope of his employment and no public service district, municipality, county, state, or any of its political subdivisions shall be liable for acts performed by off-duty law enforcement officers as permitted by this chapter.
Performance of public duty by off-duty police officer acting as private security guard. 65 ALR5th 623.