John West, who lived alone, had returned to his home on 6 April 1964. At about 3:00 am the following morning his next-door neighbour was awoken by a noise in West's house and, looking out of the window, observed a car disappearing down the street. The neighbour called the police, who found West dead from severe head injuries and a stab wound to the chest. In his house the police found a raincoat with a medallion and an Army Memo Form in its pockets. The medallion was inscribed G.O. Evans, July, 1961 and the memo form had the name Norma O'Brien on it, together with a Liverpool address. Norma O'Brien was a 17 year-old Liverpool factory worker who told the police that in 1963, while staying with her sister and brother-in-law in Preston, she had met a man called 'Ginger' Owen Evans. She also confirmed that she had seen Evans wearing the medallion.
48 hours after West's murder, Gwynne Owen Evans (real name John Robson Welby (or Walby)) and Peter Allen were arrested and charged with the crime. Evans lodged with Allen and his wife in Preston, and was also found to have a watch inscribed to West in his pocket. Both had criminal records.
Although Evans blamed Allen for beating West, he admitted to stealing the watch and under further questioning it became clear that he had masterminded the whole incident. In his turn, Allen stated that they had stolen a car in Preston and driven over to West's house so that Evans could "borrow" some money from his one-time workmate.
When Allen and Evans were tried together at Manchester Crown Court in July 1964, the charge against them was capital murder under the Homicide Act 1957. This was because the murder of West had been committed in the course of theft. During the trial the judge asked the jury to decide if the murder had actually been committed by one of the two men alone; in the latter case the other would only be found guilty of non-capital murder at the most. The jury found both men equally guilty, and both were sentenced to death by hanging.
Gwynne Owen Evans was hanged by the executioner Harry Allen at Manchester's Strangeways Prison at 8.00 a.m. on 13 August 1964. At the same time, Peter Allen was hanged at Liverpool's Walton Prison by Robert Leslie Stewart. These were the final two hangings in Britain.