The applicant, now 18, was charged with a number of offences related to sexual acts alleged to have occurred on dates in January 2023, when he was 15 years and four months old, involving a girl, also now 18, who was then 14 years and nine months old.

These included a charge under section 3 of the Criminal Law (Sexual Offences) Act 2006, which relates to engaging in a sexual act with a child under the age of 17.

A special defence of “peer consent” – dubbed the “Romeo and Juliet” defence – is available under section 3(8) of the 2006 Act, but only where a complainant was between the ages of 15 and 17 at the time of the offence.

Lawyers for the applicant argued that the unavailability of this defence in circumstances where a defendant had made a “reasonable mistake” as to a complainant being at least 15 was incompatible with the Constitution.

Firstly, they submitted that an accused who reasonably believed the child in question was at least 15 years of age lacked the requisite mens rea to justify a criminal conviction.

Secondly, they argued that the failure to make any accommodation, as part of the “peer consent” defence, for the contingency of a reasonable mistake as to age entails a breach of the guarantee of equality before the law enshrined in Article 40.1 of the Constitution.

In a 37-page judgment handed down on Friday, Mr Justice Garrett Simons noted than an argument “similar to the first argument” had previously been rejected by the Court of Appeal in Oscar v DPP [2025] IECA 278.

In respect of the second argument, the judge said the purpose of the legislation is “to protect children from inappropriate sexual activity, by reason of their immaturity and vulnerability, whilst also recognising that older children have a capacity to consent to sexual activity with their peers in limited circumstances”.

This relied on “the use of an age threshold as a proxy for maturity”, which Mr Justice Simons said was “consistent with a well-established line of case law”, having referenced the Supreme Court’s ruling in Z.G. v Ireland [2025] IESC 49.

It would be “incoherent” to allow the “peer consent” defence to be advanced based on the accused person’s belief as to age, rather than the child’s actual age, he said.

“A jury cannot meaningfully assess whether a child had consented to sexual activity in circumstances where the legislation underlying the criminal prosecution deems the child to lack the capacity to give a legally effective consent,” he explained.

Mr Justice Simons ruled:

The judge therefore dismissed the argument that there had been a breach of Article 40.1 of the Constitution.

On the question of costs, the judge expressed a provisional view that no costs order should be made against the applicant because of his reliance on legal aid and the public interest achieved by clarifying the application of the equality guarantee to the 2006 Act.

Bernard Condon SC, Brian Storan and Seán Osborne appeared for the applicant, instructed by Barry Fitzgerald Solicitors. Grainne O’Neill, instructed by the Chief Prosecution Solicitor, represented the Director of Public Prosecutions. Remy Farrell SC and Joe Holt, instructed by the Chief State Solicitor, acted for Ireland and the Attorney General.

The criminal prosecution, which had been adjourned pending the outcome of these judicial review proceedings, remains pending.