1. Introduction
This judgment clarifies the relationship between criminal trespass and an intended offence of criminal damage. Where the prosecution alleges that a person trespassed in circumstances supporting an inference of an intention to commit criminal damage, the elements of criminal damage—including the absence of lawful excuse—cannot be disregarded when assessing the trespass charge.
The judgment also gives important guidance on protective lawful excuse under section 6(2)(c) of the Criminal Damage Act, 1991. An honestly held protective motive is not enough. The damaging act must be objectively reasonable in the circumstances as the accused believed them to be, and it must be capable of protecting the person or property concerned. An asserted protective purpose that depends on a remote and highly speculative sequence of events cannot satisfy that requirement.
The appellant succeeded because the jury had not been properly directed on the linked offences as prosecuted. Nevertheless, the Court’s subsequent guidance substantially restricted the statutory argument advanced in support of his conduct. The judgment therefore combines a successful appeal based on a fundamental trial error with an explanation of why the same claimed lawful excuse should not ordinarily reach a jury on comparable evidence.
2. Background and Procedural History
The appellant and a co-accused entered a restricted area at Shannon Airport on 25 April 2017. The prosecution alleged that they acted together and damaged a US Navy aircraft by writing warnings and drawing a shape on it with marker pens. Both were charged with:
- criminal damage contrary to section 2 of the Criminal Damage Act, 1991; and
- criminal trespass contrary to section 11 of the Criminal Justice (Public Order) Act, 1994.
Both accused represented themselves at trial. The appellant did not give evidence, but the co-accused testified that they shared a common purpose. The explanation advanced was that their actions sought to protect people, particularly children, from military violence in the Middle East. The prosecution maintained that the conduct was a political protest rather than an act genuinely directed towards protecting others.
The prosecution accepted at trial that lawful excuse could, in principle, arise on the criminal damage charge. The trial judge accordingly read the relevant statutory provision to the jury. However, the prosecution maintained that lawful excuse had no application to criminal trespass, and the judge did not explain its relevance to that charge.
On 25 January 2023, the jury acquitted both accused of criminal damage but convicted them of criminal trespass. The appellant’s appeal was dismissed in [2025] IECA 186. Before the Court of Appeal, his represented case focused on the omission of a direction on the common law defence of necessity.
The Supreme Court granted leave in [2026] IESCDET 8 to consider necessity and its relationship to the elements of criminal trespass. It also invited consideration of lawful excuse in criminal damage. The Irish Human Rights and Equality Commission participated as amicus curiae, and the Attorney General was joined as notice party.
At the Supreme Court hearing, the central argument became narrower: because lawful excuse had been left to the jury on criminal damage, its significance for the linked criminal trespass charge should also have been explained.
3. Summary of the Decision
The Supreme Court allowed the appeal and directed that there be no retrial. Its principal conclusions were:
- Criminal trespass requires a reasonable inference assessed against all the evidence. Although section 11 does not require independent proof of the intended offence, an accused cannot be convicted where the evidence raises a reasonable doubt that the trespass involved the intention specified by the section.
- A lawful excuse for the intended criminal damage is relevant to the linked trespass allegation. Where the prosecution bases criminal trespass on an intention to commit criminal damage, it must address the absence of lawful excuse as part of that intended offence.
- The jury directions were fundamentally inadequate. The jury had not been instructed on an important aspect of criminal trespass as actually charged and prosecuted.
- The conviction could not safely be preserved. The Court could not speculate about the reason for the criminal damage acquittal or conclude that no miscarriage of justice had occurred.
- Protective lawful excuse has legal limits. Its availability is a mixed question of law and fact. The judge determines whether the evidence is legally capable of supporting it; the jury determines the relevant factual questions where that threshold is crossed.
- A protective causal connection is essential. Defacing an aircraft in Ireland, with the asserted aim of preventing military killings abroad through a speculative sequence of subsequent events, did not supply the required connection.
- The wider protest-rights questions remained undecided. The Court declined to resolve whether necessity or constitutional and Convention rights could justify the conduct on a different legal basis.
4. The Statutory Framework
4.1 Criminal damage: absence of lawful excuse is an element
Section 2(1) of the Criminal Damage Act, 1991 criminalises intentionally or recklessly damaging property belonging to another without lawful excuse
. That wording matters: the prosecution must establish the absence of lawful excuse, rather than treating lawful excuse simply as an exception that the accused must prove.
Section 6(2)(c) recognises a protective lawful excuse where property is damaged to protect a person, property, or a relevant property right or interest, and the acts are reasonable in the circumstances as the accused believed them to be. Section 6(3) provides that an honestly held belief need not be justified.
However, section 6 does not exhaust every possible lawful justification. Sections 6(2) and 6(5) preserve the relevance of other recognised legal grounds and defences. The Court therefore did not accept that the protective provision necessarily constituted a complete statutory code replacing common law necessity.
4.2 Criminal trespass: suspicious circumstances, not mere unauthorised entry
Section 11(1) of the Criminal Justice (Public Order) Act, 1994 covers entry as a trespasser, or presence nearby for the purpose of trespassing, in circumstances giving rise to a reasonable inference of an intention:
- to commit an offence; or
- to unlawfully interfere with property situated there.
These are distinct alternatives. Mere trespass is insufficient. The prosecution must establish the additional statutory circumstances supporting the relevant inference.
4.3 Why the distinction between the alternatives mattered
The prosecution could have formulated an allegation based on intended unlawful interference with property, if supported by the evidence. Instead, the indictment and presentation of the case tied the trespass allegation to intended criminal damage.
The prosecution was consequently required to meet the legal implications of that choice. It could not treat an intention to damage property as necessarily an intention to commit criminal damage while disregarding lawful excuse.
5. Legal Reasoning and the Precedents Applied
5.1 A reasonable inference cannot survive evidence establishing a contrary intention
The Court distinguished an offence requiring proof of actual criminal intention from one expressed in terms of circumstances supporting a reasonable inference of such intention. Nevertheless, it rejected the prosecution’s submission that suspicious circumstances could sustain conviction even where a contrary, non-criminal intention was established.
Minister for Justice v Voznuka [2009] IEHC 195 was central. In considering correspondence with an offence described in a European arrest warrant, Peart J. had interpreted section 11 as requiring circumstances reasonably supporting the statutory inference, rather than separate proof of the intended offence. Donnelly J. agreed with that interpretation.
By contrast, O'Reilly v The Governor of the Midlands Prison [2020] IEHC 201 did not establish a conflicting rule requiring proof of actual intention. The passage relied upon concerned a party’s submissions in proceedings about revocation of temporary release. It was not a substantive determination following detailed analysis of section 11.
The Supreme Court’s contribution was to explain the limits of the inference-based approach. All relevant circumstances must be considered, including evidence of the accused’s actual purpose. If the evidence raises a reasonable doubt that the accused intended an offence or unlawful interference, it cannot remain reasonable to infer that intention merely because other circumstances initially appeared suspicious.
The Court illustrated the point through a person who breaks a window to rescue someone in distress. Dark clothing, late-night activity and apparently furtive behaviour cannot be assessed while ignoring a credible rescue explanation.
The People (DPP) v Foley [1995] 1 IR 267 provided indirect support. That case concerned possession of firearms, and the acceptance that an accused’s innocent account might reasonably be true. It was not direct authority on section 11, but illustrated the ordinary principle that reasonable doubt about an essential ingredient requires acquittal.
The presumption of innocence remains decisive. The accused need not testify or call evidence. A contrary intention may emerge from prosecution evidence, including an explanation already given by the accused. Nor must the jury accept an explanation merely because it is offered: credibility and reliability remain matters for assessment against the evidence as a whole.
5.2 The indictment determines the case that must be answered
The importance of identifying the intended offence was reinforced by The People (DPP) v Flynn [2026] IESC 21 and The People (DPP) v Synnott [2016] IECA 270. These authorities treat the indictment as an integral part of due process, formally notifying the accused of the case to be met.
For section 11, the intended offence or unlawful interference must be identified, or at least clearly identifiable from the prosecution material. Further particulars may be appropriate where the indictment itself lacks sufficient detail. An amendment may also be possible if the evidence develops differently, subject to the proper procedural requirements.
Here, the particulars referred to damage, and the prosecution repeatedly relied on the alleged intention to deface the aircraft. This established that criminal damage was the foundation of the trespass allegation.
The Court also identified the significance of the indictment’s imperfect wording. It referred to an intention to damage property
, omitting the statutory qualification of unlawfulness and narrowing the broader concept of interference. Although the judge’s reference to unlawfulness addressed the omission, the prosecution could not retrospectively rely on an unrestricted allegation of interference.
5.3 A linked charge carries the legal qualifications of its intended offence
The prosecution argued that lawful excuse was irrelevant because criminal trespass required only circumstances supporting an inference of intended criminal damage. The Court rejected that separation.
Criminal damage is not merely intentional physical interference with property. It includes the requirement that the damage occur without lawful excuse. Accordingly, where the intended conduct would be lawfully excused, it cannot simply be treated as the criminal damage alleged to ground the section 11 charge.
This does not create a general statutory lawful-excuse defence to every allegation of criminal trespass. Its relevance is derivative: it follows from the elements of the particular offence said to have been intended.
Equally, an acquittal of a completed offence does not automatically defeat a charge concerning an intention to commit it. The reason for acquittal may not undermine the alleged intention. The Court’s decision depended on the inadequate directions and the particular linkage between these charges, not on an automatic rule that different verdicts are impermissible.
5.4 “Unlawful interference” requires more than the trespass itself
Although the alternative limb was not the prosecution’s operative case, the Court gave limited guidance on it. Unlawful interference may encompass tortious interference even where no particular criminal offence is intended.
However, the interference must add something to the trespass. At minimum, the contemplated interference must be more than de minimis and must affect the use or enjoyment of property. Otherwise, the additional statutory requirement would collapse into the act of trespassing itself.
The precise boundaries remain open. The Court did not comprehensively define unlawful interference, nor did it hold that criminal damage must always be intended under this alternative limb.
5.5 Fundamental misdirection and the prosecution’s changed position
On appeal, the prosecution changed its position. It argued that lawful excuse should never have been left to the jury on criminal damage and that its omission from the trespass directions was therefore immaterial.
The People (DPP) v Cronin (No 2) [2006] 4 IR 329, [2006] IESC 9 supplied the principle that an appeal must bear a relationship to the trial. Donnelly J. explained that this principle can constrain the prosecution as well as the defence. Courts should generally be slow to permit the prosecution to defend a conviction through an entirely different stance from that adopted at trial.
The People (DPP) v Bonney [2026] IESC 38 and The People (DPP) v Forsey [2019] 2 IR 417, [2018] IESC 55 qualified that principle. Appellate procedural restrictions cannot require courts to overlook fundamental legal errors or prevent consideration of points where justice requires it. The judgment did not impose an absolute prohibition on changed prosecution arguments.
The relevant statutory safeguard was section 3 of the Criminal Procedure Act, 1993, which permits a conviction to be affirmed despite a successful appellate point where no miscarriage of justice has actually occurred. The Court could not reach that conclusion here because:
- the jury had not been properly directed on a vital aspect of the trespass allegation;
- the two charges had been linked throughout the prosecution case;
- the criminal damage acquittal could have had more than one explanation; and
- attempting retrospectively to remove lawful excuse risked casting doubt on an acquittal that was not itself under appeal.
The Court refused to reconstruct the jury’s reasoning. It also emphasised that reading a statutory provision is not enough: the trial judge must explain its meaning and relate it to the issues arising on the evidence.
5.6 Lawful excuse is a mixed question of law and fact
The Court rejected the proposition that every asserted lawful excuse must automatically be submitted to the jury. The judge must first decide whether the evidence is legally capable of supporting it.
The DPP (Mullane) v Kelly [2019] 1 IR 807, [2018] IECA 378 and The DPP (Coffey) v Bennett [2016] IEHC 685 concerned obstruction of public passage without lawful authority or reasonable excuse. The former was particularly important in showing that the prosecution may establish the absence of an excuse through direct evidence or inference. It need not expressly disprove every conceivable possibility. Donnelly J. did not endorse that case’s wider description of what constitutes a legitimate protest.
R v Cairns (William) [2013] EWCA Crim 172, concerning an asserted belief in consent to property damage, similarly supported the proposition that an issue of lawful excuse must arise on the evidence. Its relevance was qualified by differences between the English and Irish legislation.
The People (DPP) v Smyth [2010] 3 IR 688, [2010] IECCA 34 was invoked by the parties in discussing the evidential basis needed for a defence. However, that discussion could not alter the statutory allocation of the ultimate burden: absence of lawful excuse remains an ingredient of criminal damage that the prosecution must prove.
The division between judge and jury was further explained through:
- The People (DPP) v McNamara [2021] 1 IR 472, [2020] IESC 34: whether evidence is legally capable of supporting provocation is initially for the judge.
- CW v DPP [2024] 3 IR 554, [2023] IESC 22: self-defence requires some evidential foundation before it is left for decision.
- The People (Attorney General) v Quinn [1965] IR 366: an accused need not prove a defence, but evidence must exist to support it.
- The People (DPP) v Davis [1993] 2 IR 1: the jury’s responsibility for determining guilt must not be displaced by a judicial direction to convict.
- The People (DPP) v Nally [2007] 4 IR 145, [2006] IECCA 128: where self-defence properly arises, the objective reasonableness of force is quintessentially a factual matter for the jury.
These principles are compatible. The judge excludes legally unsupported issues; the jury resolves genuinely available factual questions. Removing a speculative lawful excuse is not equivalent to directing a guilty verdict.
5.7 Honest belief does not eliminate objective reasonableness
The leading interpretative authority was The People (DPP) v Crawford [2024] 2 ILRM 313, [2024] IESC 44. That decision addressed lawful force under section 18 of the Non-Fatal Offences Against the Person Act, 1997. Because the amended wording of section 6(2)(c) closely resembles that provision, its partly subjective and partly objective approach also governs protective lawful excuse.
The accused’s perceived circumstances are assessed subjectively. But the damaging act must be objectively, as well as subjectively, reasonable in those circumstances. An honest belief cannot authorise an extreme or disproportionate response.
Bloxham (In Liquidation) v Irish Stock Exchange Ltd [2014] IEHC 93 supported the distinction between requiring reasonable grounds for a belief and considering those grounds as evidence of whether the belief was genuinely held. Under section 6(3), an unreasonable belief may still be honest. Nevertheless, its implausibility can inform the jury’s assessment of honesty.
The appellant’s reliance on the sample jury directions and route to verdict in The People (DPP) v Crawford did not answer the antecedent question of whether evidence existed to make the issue legally available. Guidance about directing a jury presupposes an issue properly requiring its decision.
5.8 The limited significance of the earlier Shannon Airport precedent
The People (DPP) v Mary Kelly [2012] 1 ILRM 179, [2011] IECCA 25 also concerned damage to a US military aircraft at Shannon Airport. It was particularly important because the accused in the present proceedings had relied upon it.
The earlier conviction was quashed after the trial had proceeded with confusion about amendments removing the express requirement that the person or property be in immediate need of protection
. The judge had repeatedly referred to the absence of an immediate nexus, without adequately distinguishing legal rulings from factual observations.
Donnelly J. treated that decision as narrow. It did not establish that an honestly asserted protective purpose must always reach the jury. Nor did its description of lawful excuse as highly subjective displace the objective reasonableness required by the amended statutory wording.
The distinction is important: removing an express requirement of immediacy does not remove every requirement of connection between the damage and the protection claimed.
5.9 Protective capability and the causal connection
Two English decisions helped identify the limits of the protective argument:
R v Hunt (1978) 66 Cr App R 105 concerned a person who set fire to a room to demonstrate that fire alarms did not work and thereby induce their repair. The asserted longer-term protective aim did not make the fire itself an act capable of protecting property.
R v Hill (1989) 89 Cr App R 74 concerned intended damage to a naval facility’s perimeter fence as part of an effort to secure abandonment of nuclear weapons. Taking the accused’s beliefs as true did not establish that cutting the wire could legally qualify as protecting the relevant property. The claimed protection was too remote.
The Court acknowledged academic criticism of importing objective requirements into the differently worded English legislation. Irish law, however, expressly requires objective reasonableness following the 1997 amendment.
Its reasoning proceeded in three stages:
- The evidence must raise an honestly held belief that the damage was done for protection.
- Even in the circumstances as believed, the act must be capable of contributing to that protection.
- If legally capable, its reasonableness is assessed through the proper allocation of functions between judge and jury.
Where the supposed protection depends on highly speculative future actions by others over whom the accused has no control, the necessary causal connection is absent. The judge may then withhold the issue from the jury.
Applied here, defacing the aircraft was too remote from preventing military killings abroad. The Court did not require proof that protective action would certainly succeed. Its objection was that the asserted connection itself depended on speculation piled upon speculation.
6. Necessity, Civil Disobedience and Protest Rights: What Was Not Decided
6.1 The Court of Appeal’s necessity analysis
The Court of Appeal had relied on criminal-law commentary and R v Thacker [2021] QB 644, [2021] EWCA Crim 97, involving airport security breaches intended to stop a deportation flight. It identified limitations including a real and pressing danger, an inescapable necessity without lawful alternatives, proportionality, and the absence of culpable creation of the emergency.
The Supreme Court did not conclusively settle those requirements or endorse every aspect of that analysis. Although necessity was the original focus of leave, the appeal was resolved through statutory interpretation and the defective jury directions.
6.2 The comparative protest authorities
The appellant relied on DPP v Ziegler [2022] AC 408, [2021] UKSC 23, concerning lawful excuse for obstruction of a public highway, to support an individualised proportionality assessment of protest conduct. He preferred that approach to the more restrictive authorities, including R v Thacker and R v Jones (Margaret) [2007] 1 AC 136, [2006] UKHL 16.
The prosecution and Attorney General emphasised later authorities limiting the reach of that reasoning:
- Secretary of State for Transport v Cuciurean [2023] 1 All ER 674, [2022] EWCA Civ 661, cited particularly concerning the limits of protest rights on private land; and
- In re Abortion Services (Safe Access Zones) (NI) Bill [2023] AC 505, [2022] UKSC 32, which approved that analysis and also recognised the possible inclusion of common law defences within lawful excuse.
Those authorities were discussed as part of the competing submissions, not adopted as a comprehensive Irish rule governing protest-related trespass.
The Commission relied especially on Perinçek v Switzerland App No 27510/08 (ECtHR, 15 October 2015). It argued that criminal interference with expression requires careful assessment of the particular conduct and the necessity of punishment, rather than reliance on broad categories.
6.3 Why the Court declined to resolve the wider questions
The Court found a substantial mismatch between the trial and the later rights-based arguments. At trial, the defence primarily asserted protection from killings and resisted the prosecution’s characterisation of the conduct as political protest. Later written submissions centred on freedom of expression, assembly and civil disobedience. Those questions received little developed attention at the oral hearing.
The academic material raised serious questions about moral consistency, democratic accountability and whether necessity should permit protesters to explain their motivations. But those debates could not replace a properly established factual and procedural foundation.
The Court therefore left open:
- the scope of common law necessity in protest cases;
- whether constitutional or Convention rights were engaged by this conduct;
- whether an individual proportionality assessment was required at the guilt stage;
- whether proportionality could instead be accommodated through the legislative scheme or sentencing; and
- the application of protest rights where private property is trespassed upon.
The judgment is consequently neither a general recognition nor a general rejection of a protest-based defence.
7. Why There Was No Retrial
The criminal trespass count was the lesser offence, carrying a maximum of six months’ imprisonment. The trial judge had applied section 1(2) of the Probation of Offenders Act, 1907, with a charitable donation requirement and a twelve-month bond.
That period had long expired. Given the lengthy original proceedings, the minor treatment of the offence and the practical completion of the disposition, the Court concluded that a retrial would not serve the public interest.
The criminal damage acquittal remained undisturbed. The appellant’s success did not amount to judicial approval of the defacement or acceptance of the asserted protective excuse.
8. Significance and Likely Impact
8.1 Charging decisions will require greater precision
Prosecutors must distinguish between an allegation of intended criminal damage and one of intended unlawful interference. Each has different legal implications. A clearly formulated indictment should identify the relevant intended wrong and enable the accused to understand the case.
8.2 Jury directions must explain the relationship between counts
Where one charge depends on an intention to commit another offence, directions must address the legally relevant elements and qualifications of that intended offence. A general statement that the counts are separate does not resolve their substantive connection.
8.3 The judgment preserves the prosecution burden without inviting speculation
The prosecution must prove absence of lawful excuse where it is an ingredient. But it need not rebut imaginary excuses unsupported by evidence. Equally, the accused need not personally testify or prove an excuse: the necessary evidential foundation may emerge from either side’s case.
8.4 Sincere protective motivation is not sufficient
The causal-connection requirement will matter in future direct-action cases. Courts must distinguish genuine protective action from symbolic damage whose hoped-for benefit depends on remote political or institutional responses.
That does not establish a categorical rule against every act intended to protect people abroad or avert future harm. The controlling question is protective capability in the circumstances believed, rather than geography alone. The limits of more indirect but better-supported causal connections remain for future cases.
8.5 The status of the later guidance matters
The statutory guidance followed the Court’s conclusion that the appeal should succeed and no retrial occur. It was therefore not necessary to that disposition in the narrow sense. Nevertheless, it was deliberately delivered on an issue identified as publicly important and fully connected to the trial and oral argument.
Future courts must distinguish that guidance from the reasoning necessary to quash this conviction. In particular, the Court’s conclusion that the claimed excuse lacked legal substance did not retrospectively cure the fundamental error in the trial as conducted.
8.6 Further questions remain open
Besides protest rights and necessity, the Court reserved the precise boundaries of unlawful interference and the meaning of damage in relation to temporary markings. It did not decide whether these particular markings met the statutory definition of damage, nor establish that permanent damage is required.
9. Complex Concepts Simplified
- Actus reus and mens rea
- The external elements of an offence and its required mental element. For section 11, the Court examined how trespass, surrounding circumstances and an inference of intended wrongdoing fit together.
- Reasonable inference
- A conclusion properly drawn from the evidence as a whole. Initial suspicion cannot be preserved by ignoring evidence that undermines it.
- Element of an offence versus defence
- An element must be proved by the prosecution. Criminal damage expressly includes absence of lawful excuse, although the judgment sometimes uses “defence” as convenient shorthand.
- Evidential foundation
- Some evidence making an issue genuinely available for decision. This is not the same as requiring the accused to prove innocence.
- Subjective belief and objective reasonableness
- The court considers the circumstances the accused honestly believed existed, but judges the reasonableness of the response against an external standard.
- Causal nexus
- A meaningful connection between the damaging act and the protection claimed. A sincere hope that damage might eventually prompt wider change is insufficient where the connection is highly speculative.
- De minimis
- Too trivial to meet the relevant legal threshold. The intended unlawful interference under section 11 must add something meaningful to the trespass itself.
- No miscarriage of justice
- The statutory basis on which an appellate court may preserve a conviction despite an identified error. The Supreme Court could not be satisfied of that here.
10. Conclusion
The judgment establishes that linked criminal charges cannot be analysed in artificial isolation. Where criminal trespass is founded on an inferred intention to commit criminal damage, lawful excuse for that intended damage is legally relevant and must be addressed when properly arising.
At the same time, protective lawful excuse has a firm boundary: honest motivation must be accompanied by objectively reasonable conduct capable of achieving the asserted protection. Remote, speculative hopes of influencing future events are insufficient.
The appeal succeeded because of a fundamental defect in the jury directions, not because the Court recognised a right to damage property in protest. The wider relationship between necessity, civil disobedience and freedom of expression remains for a suitably framed future case.