As of 15 December 2008, 304 prisoners who were given a mandatory, discretionary or automatic sentence of life imprisonment or a sentence to be served at Her Majesty's Pleasure on or after 1 January 1997 have been released from custody. No life sentence prisoner can be released until they have served the appropriate punitive period of imprisonment (the tariff period). The sentence planning and parole processes help ensure that such prisoners will only be released if the Parole Board is satisfied that it is safe to do so.
This figure comes from the NOMS Public Protection Unit Database. As with any large scale recording system, it is subject to possible errors arising from either data entry or processing.
It is for the independent Parole Board to determine whether the risk presented by an offender sentenced to life imprisonment is such that it might be safely managed in the community.