I would like to know what guidance/policy that governs the release of major murder case files, particularly regarding miscarriages of justice, like Christopher Craig, James Hanratty and Derek Bentley as examples.
Information held elsewhere.
Access to Records is governed by the FOI Act. When transferred to The National Archives, records are either open; or closed if they hold sensitivities covered by FOI exemptions. The decision to close any record on transfer is the originating department’s, but The National Archives does provide guidance on this procedure. You can find published guidance about the sensitivity review process on our website here.
Once at The National Archives, to help inform our decisions relating to release, we refer to published ICO guidance, or case law. In cases, such as the examples you have provided, where information may already be within the public domain, we additionally refer to TNA published guidance and more specific ICO guidance.
The National Archives does not hold a guidance/policy document specific to your request. FOI decisions are made on a case by case basis. We have provided examples, of guidance/policy used, but it is dependent on the circumstances of a case, the information a Record may hold and thus any FOI exemptions involved. From the case examples you have provided, you may find a prior FOI tribunal case of use. This explains our process and considerations in much more detail. You can find this FOI tribunal decision published on the Tribunals Judiciary website here.
Given your particular interest in miscarriages of justice you may wish to contact the Criminal Cases Review Commission (CCRC) as they specialise in this area of the justice system and therefore may hold information relevant to your request. You can contact them via their website here.