The three partial defences — loss of control, diminished responsibility and suicide pacts — that reduce murder to voluntary manslaughter, and the strict conditions each demands.
A successful partial defence makes the difference between a murder conviction with its mandatory life sentence and a manslaughter conviction with discretion in sentencing. This chapter begins with the nature of voluntary manslaughter and how a partial defence differs from a complete one, then works through loss of control: the three elements, the two qualifying triggers, the exclusions for revenge and sexual infidelity, the objective comparator test and where the burden of proof sits. It then turns to diminished responsibility — abnormality of mental functioning, recognised medical conditions, the impaired capacities and the meaning of substantial impairment — together with the difficult territory where a medical condition and voluntary intoxication overlap. It closes with the narrow defence available to the survivor of a genuine suicide pact.
