If a defendant is acquitted because he was insane when he committed the offense charged, the verdict shall be "not guilty by reason of insanity."

Source: Supreme Court Rule 406, 1939; SDC 1939 & Supp 1960, § 34.3662; SDCL, § 23-45-12; SL 1978, ch 178 , § 323; SL 1983, ch 174 , § 15.