A conviction for manslaughter was unsafe where an application to exclude evidence of confession under s.76 Police and Criminal Evidence Act 1984, for breaches of the Codes of Practice, had been refused and it later transpired it was highly likely police officers had known the defendant had a mental impairment and an appropriate adult should have been present.Reference by the Criminal Cases Review Commission ('CCRC') under s.9 Criminal Appeals Act 1995, on the basis that the defendant's ('D') conviction on 24 July 1989 at Newcastle-Upon-Tyne Crown Court for manslaughter was unsafe. On Monday 28 August 1988 the naked body of a woman ('V') was found at her flat, she had been strangled, stabbed in the chest and hit about the head with an axe like object. D knew V and had gone to her flat where the police were already in attendance. D, who had the mental age of an eight year old and was highly suggestible, went to the police station voluntarily where he was in discussion with two police officers between 9.35 am and 11.00 am. There was no formal record, D was not cautioned, no appropriate adult was present and he was not told of his right to free legal advice. D eventually confessed to murdering V, he was cautioned and a formal interview took place. However, it was still without an appropriate adult present or being told of his right to have a solicitor. D gave the police officers details of the attack. Further interviews took place, some with a solicitor present, where D repeated his admissions. The following day at a further interview, with a solicitor present, D denied he had murdered V. The police officers said they did not realise D had any mental impairment. There was no forensic evidence linking D with the killing and no other evidence save the confessions. At trial an application was made to exclude the confessions under s.76 Police and Criminal Evidence Act 1984 as there had been breaches of the Codes of Practice, in particular Code C. The judge ruled the confession evidence was admissible as, despite breaches of the Codes, the jury should hear the evidence because of its vividness and similarity with what had happened. The two police officers involved in discussions with D before the formal interview gave evidence that they had not given D any details of the attack and had not regarded him as mentally handicapped. The CCRC referred the conviction on the ground that new evidence had emerged which cast doubt on the police officer's evidence, namely, a printout from the Criminal Investigation System ('CIS') dated 28 August 1988 at 11.11 am. At the top of the document in capitals were the words "warning - mental"HELD: (1) The evidence suggested that the police officers had had the CIS printout at the time of interview, and if that was so the word "mental" would have been hard to miss. That cast a very different light on the failure to make sure an appropriate adult was present. The jury had accepted that there was no good reason for the police to have thought D was mentally impaired but had the judge and jury had sight of the CIS printout it suggested that it was at least probable that they suspected he was mentally impaired and there was therefore a much more flagrant breach of the Code. (2) The credibility of the two officers was crucial to the case. Under s.76 of the 1984 Act, the onus was on the Crown to show the confession was not taken in circumstances which rendered it unreliable. If the judge had the CIS printout it would have been bound to tip the scales in favour of D, there would then have been a successful submission of no case to answer. The conviction was therefore unsafe and would be quashed.Appeal allowed.