Robinson v The State

For diminished responsibility under the Offences Against the Person Act 1925, the decisive question is the effect of the accused’s mental abnormality on mental responsibility at the time of killing. Where schizophrenia is established, its technical aetiology is immaterial. Absence of delusions, a lucid interval, or later fitness to plead does not resolve the issue. If prosecution cross-examination raises speculative or irrelevant criticisms of psychiatric evidence, the trial judge must correct them and direct the jury to the real issue. A summing-up which leaves such matters unexplained may render a murder conviction unsafe. Obiter, a carefully scrutinised guilty plea to manslaughter by diminished responsibility may be accepted without a jury trial where there is no significant dispute and substantial impairment is clear.

The appellant challenged a murder conviction in Trinidad and Tobago, focusing on the trial judge’s treatment of psychiatric evidence supporting diminished responsibility. He had longstanding schizophrenia, and two defence psychiatrists gave evidence that it substantially impaired his mental responsibility. The prosecution challenged their evidence on delusions, lucid intervals, hearsay, the source of schizophrenia, and psychological testing. The Court of Appeal treated substantial impairment as a matter for the jury and left the conviction standing. The central issue before the Board was whether the trial process and summing-up enabled the jury properly to determine diminished responsibility.

The Board, in the judgment of Lord Hughes, allowed the appeal. The murder conviction was unsafe, was quashed, and a conviction for manslaughter on the grounds of diminished responsibility was substituted. The sentence of death was quashed and the case was remitted to the Court of Appeal for consideration of sentence or disposal.

1. Applicable issue. Under section 4A(1) of the Offences Against the Person Act 1925, the question was whether schizophrenia substantially impaired the appellant’s mental responsibility at the time of the killing. The statutory references to possible origins of an abnormality of mind enlarged rather than restricted the provision. Since chronic schizophrenia was common ground, its technical classification as disease or inherent cause was immaterial.
2. Psychiatric evidence. Absence of frank delusions or outward symptoms did not dispose of the defence. Disordered thinking, impaired judgment and loss of self-care could substantially impair responsibility. A possible lucid interval and later fitness to plead did not establish absence of illness at the relevant time. Reliance on the appellant’s account required examination only if the experts’ opinions materially depended on it. Here they did not. The challenges based on inconsistent accounts, hearsay and absent psychological tests therefore required correction.
3. Judge’s duty. The prosecution could challenge uncontradicted expert evidence by cross-examination where it had a proper basis. The judge nevertheless had to prevent speculative or unfounded suggestions being mistaken for evidence and to identify irrelevant criticisms. The summing-up merely listed several criticisms, failed to explain their significance, and left the jury with the misleading impression that they undermined the experts. It also misstated the relevance of poor judgment and socially unacceptable behaviour.
4. Safety of conviction. The combined effect of the cross-examination, closing speech and summing-up deprived the jury of the assistance needed to focus on substantial impairment. The Board therefore found the conviction unsafe. It left open when overwhelming psychiatric evidence might justify withdrawing murder from the jury or giving a particularly strong direction.
5. Acceptance of pleas. Obiter, the Board held that a guilty plea to manslaughter by diminished responsibility may properly be accepted after careful analysis where there is no significant dispute about the underlying facts or medical analysis and substantial impairment is clear. The former practice described in R v Matheson [1958] 1 WLR 474 had ceased to be followed. The considerations supporting acceptance, described in R v Vinagre (1979) 69 Cr App R 104, should apply in Trinidad and Tobago subject to equivalent safeguards.
6. Statutory consequences. Section 4A(6) did not require a jury trial whenever diminished responsibility was raised. Section 4A(3) produced the manslaughter outcome; subsection (6) concerned identification of the basis of a jury’s manslaughter verdict and discretionary detention powers. The reference to the President had to be read as a reference to the court, and subsection (7) had no remaining application. Ordinary manslaughter sentencing powers, including imprisonment for life under section 6, remained available.

• Privy Council: Appeal allowed. The murder conviction and death sentence were quashed, manslaughter substituted, and the case remitted for sentence or disposal: [2015] UKPC 34.
• Court of Appeal of the Republic of Trinidad and Tobago: Treated substantial impairment as a matter for the jury and left the murder conviction standing. No citation is stated in the judgment.