 The first problem with the evidence is the use of inmate informant evidence , such as that from Michael Wainwright , described as " the most <unk> [ form of evidence ] of all " , despite the fact that it was one of the key pieces of evidence in the trial . Glen Banks , a man with whom Park had briefly shared a cell and who claimed in court that Park had admitted his guilt to him , was described as " highly <unk> " , frequently changed his story , and also claimed that Park had admitted to killing Carol while sailing to Blackpool . Wainwright , the other informant , was said to <unk> heavy cannabis smoker and admitted to hearing voices . He claimed that Gordon had said that he went upstairs , found Carol in bed with another man , and killed her in a fit of rage . This seemed unlikely , as the Parks lived in a <unk> , and the supposed lover has never come forward . Park also claimed to have never actually met Wainwright . 
