R (on the application of Nunn) v Chief Constable of Suffolk Constabulary & Anor [2014] UKSC 37

Kevin Nunn, convicted of murder in 2006, sought ongoing police disclosure and re-testing of evidence to challenge his conviction. The Supreme Court held that post-conviction disclosure duties are narrower than pre-trial duties, limited to material casting doubt on conviction safety.

Facts

Kevin Nunn was convicted in November 2006 of the murder of his former girlfriend, Dawn Walker, whose body was found by a river two days after their relationship ended. The Crown case rested on motive, his jealous disposition, his admitted presence with the deceased on the evening of her disappearance, evidence of an argument overheard by neighbours, his possession of a covert key to her home, and identification evidence of him removing a large wrapped object from her house. Nunn’s application for leave to appeal was refused in October 2007.

From 2008 onwards, Nunn made repeated requests to the police for access to investigation records, forensic scientists’ working papers, and for further scientific testing of exhibits, with a view to challenging his conviction as a miscarriage of justice. The requests initially ranged widely, including into the deceased’s finances and possible links to unrelated murders of Ipswich prostitutes, before narrowing to forensic materials and DNA re-testing. The police accepted a duty to disclose material coming to light that might cast doubt on the conviction’s safety, but refused to facilitate a general trawl of concluded case files. Nunn sought judicial review; the Divisional Court refused relief.

Issues

The certified question was whether the disclosure obligations of the Crown following conviction extend beyond a duty to disclose material that might materially cast doubt upon the safety of a conviction, such that the Chief Constable was obliged to disclose the material sought. Centrally, the court had to determine whether the common law duty of disclosure applicable pre-trial continues in identical form after conviction and exhaustion of appeal rights.

Arguments

Appellant

Mr Southey QC contended that the statutory duties under sections 3 and 7A of the Criminal Procedure and Investigations Act 1996 merely enacted a pre-existing common law duty; that the common law duty subsists after trial; that its purpose is to prevent miscarriages of justice; and accordingly that the Crown owed Nunn the same disclosure and inspection duty after conviction as it had owed before and during trial, including the obligation to respond to renewed requests for access and further testing.

Respondents

The Chief Constable and CPS argued that the post-conviction duty is limited to disclosing material that might cast doubt on the safety of the conviction, as reflected in paragraph 72 of the Attorney General’s Guidelines, and that there is no obligation to permit an open-ended re-investigation at the convicted person’s request.

Judgment

Lord Hughes, giving the judgment of the court, dismissed the appeal. The court held that the common law duty of disclosure was never uniform across all stages of the criminal process; rather, it has always been tailored to the requirements of each stage. Before committal (R v DPP, Ex p Lee [1999] 1 WLR 1950), pending sentence, and pending appeal, the duty exists but is narrower than the full pre-trial duty. The statutory duty under the 1996 Act, which by section 7A(1)(b) ends at conclusion of trial, does not apply to Nunn.

The court reviewed comparative authority from New Zealand (Nepia; Cant), Canada (Trotta; Stinchcombe), Scotland (McDonald v HM Advocate) and the United States (District Attorney’s Office v Osborne), all of which recognise a material difference between pre-trial and post-conviction disclosure. The convicted defendant is no longer presumed innocent; he has exhausted his right to make full answer and defence; and although there is a strong public interest in correcting miscarriages of justice, there is also a powerful public interest in finality.

The court held that after conviction and exhaustion of appeal, the duty is that stated in paragraph 72 of the Attorney General’s Guidelines: where material comes to light that might cast doubt on the safety of the conviction, the prosecutor must consider disclosure — meaning must disclose unless there is good reason not to. To this the court added that if there exists a real prospect that further enquiry may reveal something affecting the safety of the conviction, that enquiry ought to be made. There is, however, no continuing duty to respond to speculative requests or to allow indefinite re-investigation.

The court emphasised the role of the Criminal Cases Review Commission as the statutory safety net, with extensive investigative powers, including the ability to direct new scientific testing. Judicial review remains available, but relief will generally be inappropriate until the CCRC has had the opportunity to make a reasoned decision. On the facts, Nunn’s requests were largely speculative: his own forensic report raised no query with the original scientific work, and further DNA testing would not necessarily exclude him as the killer given the trial’s exploration of secondary transfer.

Implications

The decision clarifies that the Crown’s post-conviction disclosure obligation is materially narrower than the pre-trial duty. Police and prosecutors must disclose material coming into their possession that might cast doubt on the safety of a conviction, and must co-operate with further enquiries where there is a real prospect that they may uncover such material, as illustrated by R v Hodgson [2009] EWCA Crim 490. They are not, however, obliged to entertain speculative or open-ended fishing expeditions by convicted persons.

The judgment reinforces the CCRC’s central role as the appropriate mechanism for investigating alleged miscarriages of justice after appellate rights are exhausted, and signals that judicial review will generally be premature before the CCRC has considered a case. The decision balances the public interest in correcting wrongful convictions against the interests in finality and the efficient allocation of finite police resources. It matters to convicted persons, their legal representatives, police forces, prosecutors, and organisations engaged in miscarriage-of-justice work, providing a workable framework for co-operation while resisting unlimited post-conviction re-investigation. The court also acknowledged that advances in scientific testing may in future generate genuine grounds for renewed enquiry, and that sensible judgment by police and prosecutors — rather than reflexive resistance — is expected.

Verdict: Appeal dismissed. The Supreme Court held that the Crown’s post-conviction disclosure duty is limited to disclosing material that might cast doubt on the safety of the conviction, and to making further enquiry where there is a real prospect it may reveal such material; there is no continuing duty identical to the pre-trial disclosure obligation.

Source: R (on the application of Nunn) v Chief Constable of Suffolk Constabulary & Anor [2014] UKSC 37