The secretary of corrections may place, on a six-month supervised furlough, any inmate who is classified at a custody level not higher than minimum and who will be eligible for parole under K.S.A. 22-3717, and amendments thereto, by the end of the six-month period. If, at the end of the six-month period, the secretary determines that the inmate has successfully completed the furlough, the secretary shall certify that fact to the prisoner review board, which shall promptly order the inmate’s release on parole, without hearing, under the level of supervision specified by the secretary and subject to such conditions as imposed by the board. The provisions of this section shall not apply to crimes committed by inmates on or after July 1, 1993.