"... this was the planned ambush and robbery of a drug dealer in circumstances where [the appellant] was armed with a knife which he intended to produce in order to reinforce his demands and as events demonstrated was prepared to use if necessary. It is [likely] that the plan to rob Asad Hussain was conceived by Ayub Khan but on any view of matters [the appellant] played a central role in the execution of that plan. He was present when the phone call was made to Asad Hussain for arranging the meeting; he was the person who acted as the drugs purchaser; he was armed with a knife and he was the person that used it to kill Richard Hopley. This was a single blow but it was delivered with severe force to a vulnerable part of the body and I have no doubt that at the time of the stabbing [the appellant] intended to kill."