The loss of control defence is a partial defence to the crime of murder in the jurisdiction of England and Wales. It was created by section 54 of the Coroners and Justice Act 2009.[1] The definition of "loss of control" in the Act is defined in a way that requires multiple requirements to be met, and with a number of listed exceptions that can render the defence inapplicable.
In particular, for a defendant to rely on the defence, there must either be "fear of serious violence", or the combination of "circumstances of an extremely grave character" and a "justifiable sense of being seriously wronged". Revenge for sexual infidelity is specifically ruled out as a qualifying trigger, although R v Clinton has interpreted this exception as applying only to cases where sexual infidelity is the single cause of loss of control.[2]
The loss of control defence does not exonerate the person who loses control; instead it downgrades the charge for that person from murder to manslaughter, and does not change the nature of the offence for other perpetrators who may have been involved.[1]
The partial defence of loss of control was introduced to replace the partial defence of provocation, which was abolished by the same legislation.[3][4]