The board shall issue an order authorizing the parole which must be signed by at least a majority of its members with terms and conditions, if any, but at least two-thirds of the members of the board must sign orders authorizing parole for persons convicted of a violent crime as defined in § 16-1-60. The director, or one lawfully acting for him, then must issue a parole order which, if accepted by the prisoner, provides for his release from custody. Upon a negative determination of parole, prisoners in confinement for a violent crime as defined in § 16-1-60 must have their cases reviewed every two years for the purpose of a determination of parole.