Foy, R. v

Fresh expert evidence will ordinarily be refused where a potential defence was fully investigated before trial, an appropriately qualified expert reached a conclusion reasonably open on the available material, and the proposed evidence merely advances a different post-conviction opinion. The interests of justice under section 23 of the Criminal Appeal Act 1968 require finality and do not permit expert shopping or a second attempt at a defence that could and should have been run at trial.

For diminished responsibility under section 2 of the Homicide Act 1957, acute psychosis caused by voluntary alcohol or drug use is not a recognised medical condition. A concurrent recognised medical condition may support the partial defence only if the statutory requirements are independently proved on the balance of probabilities.

The appellant was convicted at the Central Criminal Court of murdering a stranger whom he stabbed while experiencing a psychotic episode after voluntarily consuming substantial quantities of alcohol and cocaine. At trial, the defence advanced was absence of the intent required for murder. The jury rejected it.

Diminished responsibility had been considered before trial. The defence psychiatrist concluded that the psychosis was overwhelmingly likely to have been caused by alcohol and cocaine, so that the defence could not be established. After conviction, a new psychiatrist expressed a contrary opinion based on substantially the same material.

The appeal raised whether the new psychiatric evidence should be admitted under section 23 of the Criminal Appeal Act 1968 and, if admitted, whether it disclosed a viable defence of diminished responsibility under section 2 of the Homicide Act 1957 so as to render the murder conviction unsafe.

1. Appeal dismissed. The application to adduce the proposed fresh psychiatric evidence was refused. The trial defence of diminished responsibility had been carefully investigated before trial. The original expert had the material needed to reach an informed diagnosis, and his conclusion was reasonably open to a responsible psychiatrist. The new evidence was substantially a later contrary expert opinion, not evidence of a legal error, an overlooked material, or a material new development.

2. Under section 23 of the Criminal Appeal Act 1968, the interests of justice ordinarily require a defendant to advance the whole case at trial. The court followed the rigorous approach in Erskine and Williams [2009] EWCA Crim 1425, Evans [2009] EWCA Crim 2243 and Challen [2019] EWCA Crim 916. An appeal is not a means of obtaining a second opinion after a defence, available at trial, has failed. Admitting the evidence would risk subverting the trial process, including by reopening the separate issue of intent.

3. The court also held that the evidence could not establish a viable diminished-responsibility defence. Under section 2 of the Homicide Act 1957, the appellant had to prove that an abnormality of mental functioning arose from a recognised medical condition, substantially impaired a specified ability, and explained the killing. Acute psychosis caused by voluntary intoxication cannot itself supply the recognised medical condition. Voluntary intoxication does not necessarily bar the defence where an independent recognised medical condition satisfies the statutory requirements, but there must be proper evidence of each element.

4. On the proposed evidence, once the voluntarily ingested alcohol and cocaine were excluded, there was no solid evidential basis for a recognised medical condition causing a qualifying abnormality, substantial impairment, and a statutory explanation for the killing. The proposed diagnosis was insufficiently grounded in the medical and prison records. The conviction for murder was therefore safe.

• Court of Appeal (Criminal Division): dismissed the appeal and refused permission to adduce fresh psychiatric evidence: [2020] EWCA Crim 270.
• Central Criminal Court: convicted the appellant of murder on 12 February 2018 and imposed life imprisonment with a minimum term of 17 years.