S.C. Code Ann. § 17-24-30: Form of verdict.

In a prosecution for a crime when the affirmative defense of insanity is raised sufficiently by the defendant, or when sufficient evidence of a mental disease or defect of the defendant is admitted into evidence, the trier of fact shall find under the applicable law, and the verdict must so state, whether the defendant is:

(1) guilty;

(2) not guilty;

(3) not guilty by reason of insanity; or

(4) guilty but mentally ill.