CJA 2009 § 52
Definition
Coroners and Justice Act 2009 § 52, amending Homicide Act 1957 § 2: the defendant must show an abnormality of mental functioning arising from a recognised medical condition that substantially impaired understanding, rational judgement, or self-control, and that explains the killing.
- Statute
- Coroners and Justice Act 2009, Section 52
- Amends
- Homicide Act 1957, Section 2
- Defence to
- Murder, reducing it to manslaughter
- Requires
- Recognised medical condition substantially impairing understanding, judgement or self-control
Common questions
What changed compared to the original 1957 diminished responsibility defence?+
The 2009 amendment replaced the older, looser test of 'abnormality of mind' with a tighter requirement that the abnormality arise from a recognised medical condition and specify which of three named functions it substantially impaired, narrowing the psychiatric evidence needed.
Who bears the burden of proving diminished responsibility under this section?+
The defendant bears the burden of proving the defence on the balance of probabilities, which is a lower standard than the prosecution's burden to prove guilt beyond reasonable doubt on the underlying killing.
What role does a forensic psychiatrist play under this test?+
A forensic psychiatrist assesses whether the defendant had a recognised medical condition at the time of the killing and gives an opinion on whether it substantially impaired the specific functions the statute names, forming the medical evidence the defence relies on.
Related terms
- Atkins V. Virginia (2002)
- US Supreme Court ruling categorically prohibiting the execution of intellectually disabled defendants under the Eighth Amendment; Hall v. Florida (2014) and Moore...
- Battered-Woman Syndrome (BWS)
- Described by Lenore Walker (1979): a pattern of learned helplessness, hypervigilance to danger cues, and disrupted threat perception resulting from sustained intimate-partner...
- Diminished Responsibility
- A partial defence that reduces murder to manslaughter in the UK (Homicide Act 1957 § 2 as amended by Coroners and Justice...
- Lockett V. Ohio (1978)
- US Supreme Court ruling under the Eighth Amendment requiring that sentencers in capital cases must be able to consider any aspect of...
- Miller V. Alabama (2012)
- US Supreme Court ruling prohibiting mandatory life-without-parole sentences for offenders who were under 18 at the time of their offence, on the...
- Recognised Medical Condition
- The diagnostic threshold in CJA 2009 § 52, aligning the UK diminished-responsibility defence with DSM-5 / ICD-11 categories; prevents non-diagnostic emotional or...
- Roper V. Simmons (2005)
- US Supreme Court decision prohibiting capital punishment for offenders who were under 18 at the time of their crime, resting in part...