The board shall: I. Be responsible for paroling prisoners from the state prison and recommitting those who have violated the conditions of parole, subject to the applicable provisions of this chapter; II. Have legal custody of all persons released on parole until they receive their discharge or are recommitted to the prison; III. Adopt rules, pursuant to RSA 541-A, relative to: (a) The parole process, including the conduct of parole hearings; (b) Criteria used to evaluate prospective parolees; (c) Conditions for the conduct of parolees; and (d) Procedures for revocation of parole. (e) Procedures for medical parole.