the mens rea for murder is malice aforethought, express or implied
malice aforethought does not need to be proved - murder does not need to be pre-meditated or malicious
express malice is the intention to kill
implied malice is the intention to do gbh
vickers confirmed that the intention to do gbh is sufficient to satisfy a murder conviction
murder cannot be committed recklessly so the principle of indirect intention is important - mathews and alleyne
in order to establish indirect intention, it must be proved that the defendant foresaw the criminal consequence as a virtually certain consequence and continued anyway