The Director is authorized to determine those prisoners who may be suitable parole risks and whose interests and those of society will be served by their early parole release and to recommend such prisoners to the Parole Board for early parole consideration. In making such recommendation, the Director shall take into account the prisoner’s criminal history record, mental and physical condition, employability, institutional adjustment and such other factors as may be appropriate, including the risk of violence to others. The case of any such prisoner so recommended may be reviewed by the Parole Board prior to such prisoner’s date of eligibility for parole. Upon appropriate review the Parole Board may release on parole prior to the date of eligibility for parole any prisoner so recommended by the Director. However, no prisoner shall be released until he has served at least one-fourth of the term of imprisonment imposed, or until he has served twelve years of the term of imprisonment imposed if one-fourth of the term of imprisonment imposed is more than twelve years, except as such time is reduced by any other provision of law. This section shall have no application to persons not eligible for parole pursuant to subsections B, B1 and E of § 53.1-151.