When the Commissioner of Mental Health determines that a person whose sentence has not expired no longer requires to be under the supervision of the Department of Mental Health, the Commissioner shall return the person to the custody of the Commissioner in accordance with 18 V.S.A. chapter 189. (Added 1971, No. 199 (Adj. Sess.), § 20; amended 1989, No. 187 (Adj. Sess.), § 5; 1995, No. 174 (Adj. Sess.), § 3; 2007, No. 15, § 22.)