The post you are reporting:
Vic the case to which you refer contained the anomaly in the English law was indeed the lack of a concept of 'diminished responsibility' between 'criminal insanity' and guilt when the murderer had not been insane, but not in a normal mental state either, the jury could only find him guilty and send a recommendation for mercy to the Home Secretary. This problem got enormous publicity late in 1952, when a sixteen-year-old Croydon boy, Christopher Craig, murdered a policeman during a burglary attempt. His accomplice, the nineteen-year-old Derek Bentley, had been held by the police for a while by the moment Craig fired the fatal shot, but they were both found guilty of the murder. The case became even more outrageous when Craig escaped hanging because of his age, but Bentley, under arrest when the murder was committed and mentally on the level of a child, was sentenced to death. The sentiment of the public was clearly on his side, and petitions for mercy were signed by huge numbers of people, including 200 MPs from all parties. But the Home Secretary, Sir David Maxwell-Fyfe, was known for being exceptionally blunt towards murderers' appeals, and even the pleas of his fellow Conservative politicians in the name of political expediency failed to convince him. Bentley was hanged in January 1953 . Later that year, the Gowers Commission released its extensive report, one not fulfilling the wishes of the Government. If there was to be any reform in death penalty law, it concluded, it should be the abolition of capital punishment. Again no action whatsoever was taken by the Government, and executions went on.
You will note that this murder falls under para's 3 and 6 above and he did not get executed simply cos he carried a gun.