Information recorded on the prison IT system as at May 2006 shows that 53 life sentence prisoners who were sentenced from 2000 onwards have been released on licence. In one of these cases the prisoner was later recalled to custody and subsequently released for a second time.
The main criteria governing the release of the 53 lifers were that they had served the period of imprisonment necessary for the purposes of retribution and deterrence (the tariff) and that their risk to the public was acceptable. Since October 1992, the responsibility for the release of tariff expired life sentence prisoners has gradually transferred from the Home Secretary to the Parole Board.
In considering the possible release of any tariff expired life sentence prisoner, the Parole Board is required by statute to satisfy itself that
"it is no longer necessary for the protection of the public that the prisoner should be confined".