Golds, R v

For diminished responsibility, substantially impaired requires more than an impairment that is merely trivial or minimal. The impairment must be real or appreciable, but need not be total. The question remains one of degree for the jury.

A judge may ordinarily leave the statutory word to the jury's common sense. If further assistance is needed, a direction should make clear that a modest impairment may still fall short of substantial impairment. Evidence of prior violence may be admissible under the relevant gateway in the Criminal Justice Act 2003 where it concerns an important matter in issue, even though it does not establish propensity.

The appellant admitted killing his partner but relied on diminished responsibility under section 2 of the Homicide Act 1957. Three medical experts considered that he suffered from a recognised mental condition which substantially impaired relevant abilities, but the jury convicted him of murder.

At the Crown Court at Chelmsford, the judge admitted evidence of an alleged earlier admission of domestic violence, declined to place before the jury evidence given by Dr Blandford at a voir dire about the appellant's then current condition, and gave no further definition of substantially impaired. The appellant appealed against conviction, contending that those rulings and directions rendered the conviction unsafe.

1. Appeal dismissed. None of the challenged rulings or directions made the murder conviction unsafe.
2. The evidence of the alleged earlier admission of violence was not properly admissible as important explanatory evidence under section 101(c) of the Criminal Justice Act 2003. However, it was admissible under gateway (d). It concerned the important issue whether there was a background of violence in the relationship. That could bear on the appellant's capacity for self-control and on whether the factual history supplied to the medical experts was reliable. The evidence did not show a propensity to commit the fatal attack, and the jury was directed accordingly. The appellant's inability to give evidence did not make admission unfair, although it was relevant to the jury's assessment of reliability.
3. The omission of an express caution that the appellant could not answer the allegation was undesirable but immaterial. The jury had been told not to draw an adverse inference from his silence. There was other evidence concerning alleged domestic violence, so the omission did not cast doubt on the verdict's safety.
4. The judge was entitled to exclude Dr Blandford's voir dire evidence about the appellant's current mental state. It would not materially assist the jury in determining his mental condition at the time of the killing. Any later deterioration could have resulted from the trial or remand in custody.
5. Under section 2(1)(b) of the Homicide Act 1957, an impairment is not substantial merely because it is more than trivial or minimal. The authorities treat the issue as one of degree, between minimal and total impairment. A judge need not define this ordinary statutory word unless the jury needs assistance. If a fuller direction is appropriate, the Simcox formulation is preferable because it makes clear that a modest impairment may not be substantial. The judge therefore did not err by declining to give the proposed direction or a fuller definition.

• Court of Appeal (Criminal Division) — dismissed the appeal against conviction: [2014] EWCA Crim 748.
• Crown Court at Chelmsford — on 11 June 2013, convicted the appellant of murder and imposed life imprisonment with a minimum term of 15 years.