Greenwood's trial began on 2 November 1920 at Carmarthen assizes before Mr Justice Shearman; he was prosecuted by Sir Edward Marlay Samson and defended by Sir Edward Marshall Hall. The case was Hall's third murder trial of the year, and he was already in poor health; however, he decided to accept the brief, despite doubts expressed by others, claiming "The man's innocent, and I'll get him off – you'll see".
