It is a mandatory requirement that prisons check the correctness of the calculation of a prisoner’s release date 14 days and two days before release. At this point, a check is also made to ensure that there is no other reason a prisoner should be detained in custody, such as, if they are remanded to custody on further charges or held on immigration matters. Additionally, re-calculations and checks are also carried out during the course of the sentence should a prisoner be transferred from one establishment to another. Prison Service Order 6650 provides details of the sentence calculation checks required.
The number of known releases in error are reported to the national operations unit in the National Offender Management Service (NOMS) by prison establishments. The number of releases reported is as follows:
Number of releases in error (RIEs) reported Total number of prisoner discharges Percentage of discharges that are RIEs 2005 32 84,500 <0.04 2006 36 78,535 <0.05 2007 36 77,146 <0.05 2008 57 n/a — n/a = Not available.
Number of releases in error (RIEs) reported
Total number of prisoner discharges
Percentage of discharges that are RIEs
n/a = Not available.
Information on how early the release was in each case and the details of the offences are not available centrally and could be obtained only at disproportionate cost.
The number of releases in error remains very small as a percentage of total discharges (less than 0.05 per cent. in 2007, the last year for which discharge figures are currently available) and must be viewed in the context of increased prisoner movement to accommodate the rising population.