In a recent case, D admitted killing his partner by stabbing her multiple times following an argument, but he pleaded diminished responsibility. The evidence of three medical experts was that it was their belief that at the time D had been suffering from an abnormality of mental functioning which ‘substantially impaired’ his ability to understand, for instance, the nature of his conduct or to exercise self-control. This explained D’s conduct in that it had caused, or was a significant contributory factor in causing, him to carry out that conduct – thus establishing diminished responsibility under s2 Homicide Act 1957.