Judge correctly identified burden of proof for diminished responsibility in murder trial, man’s conviction upheld



A man has lost an appeal against his conviction for murder after unsuccessfully arguing the trial judge had incorrectly advised the jury as to the standard of proof in relation to the defence of diminished responsibility.

Joseph Heffernan appealed to the Court of Appeal against his conviction for the murder of Eoin Ryan.

At trial, the jury had heard that after killing Mr Ryan, Mr Heffernan had called the Gardaí claiming that he had “killed a man, that the devil was in him and that he came on to the appellant and he killed him”.

The main issues in the case centred around Mr Heffernan’s mental state at the time of the killing, with his counsel submitting a defence that as a result of a mental disorder as defined in the Criminal Law (Insanity) Act 2006, “his responsibility for the act was substantially diminished such that he should be found not guilty of murder but guilty of manslaughter on the ground of diminished responsibility”.

The judge had advised the jury that in order to succeed with this defence, it must be proven on the balance of probabilities.

At appeal, the defence argued that this amounted to a material misdirection on the part of the trial judge, in suggesting that the appellant was required to discharge a legal burden of proof and in suggesting that the standard of proof was proof on the balance of probabilities.

The issue rested on how to correctly interpret s.6 of the Criminal Law (Insanity) Act 2006.

The section allows for an accused to be found guilty of manslaughter rather than murder if the defence “establishes” that the accused was suffering a mental disorder which was not enough to justify a finding of not guilty due to insanity, but diminished substantially their responsibility for the act.

Counsel for the defence argued that this section placed an evidential burden only on the accused, meaning that they had only to raise a reasonable doubt as the killing being murder on account of the possibility of diminished responsibility.

Counsel acknowledged a recent case, The People (Director of Public Prosecutions) v. Smyth 3 I.R. 688 was against him, as it stated that diminished responsibility was a special defence which case a legal burden of proof to be proven on the balance of probabilities.

However, defence counsel argued from first principles, notingWoolmington v DPP A.C. 462 and McGowan v Carville I.R. 330 which establish the fundamental principle that the prosecution must prove the guilt of the accused.

It was submitted that at common law, there had been an onus on the defendant to prove insanity, as shown in the cases of M’Naghten’s case (1843) 10 Cl. & Fin. 200; People v Messitt I.R. 204; and D.P.P. v. Redmond 3 I.R. 188.

However, counsel argued that this rule arose from the fact that murder used to be punishable by death, and that it was difficult to prove sanity, providing strong incentives for individuals to feign insanity.

Turning to the 2006 Act, counsel submitted that it aimed to “modernise and revamp” the law. As the Act does not state the burden of proof, it was argued that it should be assumed to not have adopted the common law rules which shift the onus of proof onto the accused.

It was submitted that the Court should read the Act in a constitutional manner, with the constitutionality of a provision that shifted the burden of proof to the defendant must be doubted.

Counsel for the prosecution argued that following the definition of the word “establish” in Blacks Law Dictionary, it must be taken to mean that the accused bears the onus of proof.

The People (Director of Public Prosecutions) v. Smyth was cited as further support for this position.

Delivering the judgment, the Court found that the appellant’s contentions were not well founded.

It was observed that even in Woolmington v DPP A.C. 462, which places the onus for proving guilt on the prosecution, it was noted that the defence of insanity was an exception, and that this exception had long existed in the common law.

Using the rules of interpretation contained within the Interpretation Acts 1937 to 2005, the Court considered the Act of 2006 as a whole, and the place of s. 6 dealing with diminished responsibility within the scheme of the Act.

The Court found that the Act did amend the common law in a number of ways.

Section 6 “indisputably introduces a wholly new limited statutory defence based on diminished responsibility, and for which there was no provision at common law.”

However, in relation to the standard of proof in such cases, the Court found that “it would be a mistake to rush to a judgment, as we are in effect being invited to do by the appellant, that the Oireachtas, in the absence of express wording evincing an intention on their part to continue with the anomalous historical approach, intended to discard it.”

The Court found that “Whether the public policy considerations underpinning the common laws rules as to the burden and standard of proof in insanity cases, are based on a concern about sane persons escaping criminal liability on the basis of tenuous insanity pleas, or upon the great difficulty in proving a person’s sanity to the standard of beyond reasonable doubt, it seems to this Court that there is nothing in the Act of 2006 to suggest that the Oireachtas had arrived at the view that such legitimate considerations no longer obtain or that they ought to be rejected as obsolete.”

Tunring to s.6 of the Act, it was found to be linked with s.5, which contains the defence of insanity.

First, the concept of “mental disorder” which appears in both s.5 and s. 6 is a shared and common one. Secondly, to successfully avail of the defence of diminished responsibility an accused must establish, inter alia, that “the mental disorder was not such as to justify finding him or her not guilty by reason of insanity”.

Thus, the entitlement to avail of diminished responsibility is therefore made directly referable to, and must be measured against, the requirements for establishing insanity. In addition, of course, it must be further established that “the mental disorder … was such as to diminish substantially his or her responsibility for the act.”

Thus, the Court found that “Accordingly, when s. 6(2) of the Act of 2006 states that “it shall be for the defence to establish” that the accused is not liable to be convicted of murder, it is, in our view, clear beyond peradventure that this means that the accused bears the burden of persuasion in respect of his entitlement to avail of the partial defence, and that it is a burden of persuasion to the same standard as would apply if he was relying on the defence of insanity, namely proof on the balance of probabilities.”

  • by Rachel Killean for Irish Legal News