JUDGMENT NO. 33

YEAR 2026

REPUBLIC OF ITALY

IN THE NAME OF THE ITALIAN PEOPLE

THE CONSTITUTIONAL COURT

Composed of:

President: Giovanni AMOROSO;

Judges: Francesco VIGANÒ, Luca ANTONINI, Stefano PETITTI, Angelo BUSCEMA, Emanuela NAVARRETTA, Maria Rosaria SAN GIORGIO, Filippo PATRONI GRIFFI, Marco D’ALBERTI, Giovanni PITRUZZELLA, Antonella SCIARRONE ALIBRANDI, Massimo LUCIANI, Maria Alessandra SANDULLI, Roberto Nicola CASSINELLI, Francesco Saverio MARINI,
has rendered the following

JUDGMENT

in the constitutional legitimacy review proceeding concerning the combined provisions of Article 20, first paragraph, first sentence, and second paragraph, of Law of 18 April 1975, no. 110 (Provisions supplementing the existing discipline for the control of arms, ammunition, and explosives), initiated by the Ordinary Court of Reggio Calabria, Criminal Section, in a single-judge composition, in the criminal proceedings against G. B. by order of 24 October 2024, registered under no. 37 of the register of orders for 2025 and published in the Official Gazette of the Republic no. 10, special first series, of the year 2025.

Having seen the intervention of the President of the Council of Ministers;

Heard in the Chamber of Council on 12 January 2026 the Reporting Judge Filippo Patroni Griffi;

Deliberated in the Chamber of Council on 12 January 2026.

Facts Considered

1. – By order of 24 October 2024, registered under no. 37 of the register of orders for 2025, the Ordinary Court of Reggio Calabria, Criminal Section, in a single-judge composition, raised questions of constitutional legitimacy regarding the combined provisions of Article 20, first paragraph, first sentence, and second paragraph, of Law of 18 April 1975, no. 110 (Provisions supplementing the existing discipline for the control of arms, ammunition, and explosives), in reference to Articles 2, 3, 24, 25, second paragraph, and 117, first paragraph, of the Constitution, the latter in relation to Article 7 of the European Convention on Human Rights.

The first of the challenged provisions imposes upon anyone – other than those professionally engaged in matters of arms or explosives or authorized for the collection or accumulation of arms – the obligation to ensure the custody of such objects "with all due diligence in the interest of public safety”. Pursuant to the second provision, failure to comply with this requirement is punishable, if the act does not constitute a more serious offence, by arrest from one to three months or a fine up to EUR 516.00.

2. – The referring judge premises that they are called to hold the pre-trial hearing referred to in Article 554-bis of the Code of Criminal Procedure, following a direct citation to trial of an individual not engaged in the trade or collection of arms, charged with the contravention offence under Article 20, second paragraph, of Law no. 110 of 1975, "because, in the custody of the short and long firearms (with related ammunition) legally held at his residence […], he failed to observe the diligence necessary to ensure [non-]easy access to the same by unauthorized persons, thereby endangering public safety”.

At this procedural stage – states the referring judge – the judge must perform the review required by Article 554-ter of the Code of Criminal Procedure and, therefore, alternatively, set the trial hearing for the continuation of the proceedings based on an assessment of the "reasonable prospect of conviction” or issue an order of non-prosecution to conclude the trial.

2.1. – Regarding relevance, the referring judge illustrates that, based on the factual elements gathered, neither causes for the extinguishment of the offence nor the cause for exclusion of punishability due to the particular insignificance of the act pursuant to Article 131-bis of the Criminal Code would apply in the case under examination, so that the proceedings should continue to the trial stage. Conversely, a possible declaration of unconstitutionality of the criminalizing provision would lead to an immediate conclusion of the trial through the issuance of an order of non-prosecution because the act would no longer be provided for by law as an offence.

To support this conclusion, the order reviews the findings resulting from the documents contained in the public prosecutor’s file:

– the defendant is the holder of a firearms license and keeps five rifles and one pistol in his residence, stored in a safe located along the residence’s hallway;

– the defendant’s son, without his knowledge, used one of these rifles to attempt suicide, inflicting a gunshot wound upon himself;

– the young man, cohabiting with his father, suffers from psychiatric conditions (schizophrenia) for which he has been receiving long-term treatment at the mental health centre;

– it has not been clarified whether the safe was locked at the time of the incident.

In light of these evidentiary findings (and, in particular, due to the easy access to the weapons by family members, the stable cohabitation between father and son, and the latter’s precarious health condition), the Court of Reggio Calabria observes that the defendant was required to maintain a standard of diligence in the overall custody of the weapons higher than that actually observed.

The referring judge then excludes the applicability of the subsidiary clause provided for in Article 20, second paragraph, of Law no. 110 of 1975, according to which the contravention offence is excluded if the act constitutes a more serious offence. In particular, the defendant would not exhibit aspects of improper omission liability for intentional injury pursuant to the combined provisions of Articles 40, second paragraph, and 582 of the Criminal Code, nor aspects of omission liability for negligent injury pursuant to the combined provisions of Articles 40, second paragraph, and 590 of the Criminal Code. The parent, in fact, would have no legal obligation to prevent the event, given that, on the one hand, the son has reached the age of majority and, on the other hand, has not been legally interdicted.

2.2. – Regarding non-manifest unfoundedness, the referring judge initially stresses that, of the criminal offences provided for by the combined provisions of the first and second paragraphs of Article 20 of Law no. 110 of 1975, they intend to challenge only the violation of the conduct described in the first period of the first paragraph and not that of the second period, aimed at individuals who – unlike the defendant – professionally engage in matters of arms or explosives or are authorized for the collection or accumulation of arms.

Having clarified this, the Court of Reggio Calabria raises two sets of issues.

2.2.1. – Firstly, the violation of Articles 25, second paragraph, 24, and 117, first paragraph, of the Constitution, the latter in relation to Article 7 of the ECHR, is alleged.

From a first perspective, the challenged provision would violate the principle of certainty and definiteness imposed by Article 25, second paragraph, of the Constitution.

Indeed, the criminal offence would be simultaneously contradictory and vague: on the one hand, the legislature punishes the failure to comply with "provisions” – thus using a term that in abstract refers to specific and detailed commands or prohibitions – but on the other hand, it identifies one of the required conducts in mere "diligence”, thus using a vague and discretionary concept.

According to the referring judge, the phrase used in the second period of the first paragraph of the challenged Article 20, which refers to the "procedures prescribed by the public security authority,” cannot remedy the definition of the offence, as this phrase refers to the conduct imposed on those who professionally engage in matters of arms or explosives or are authorized for the collection or accumulation of arms. Moreover, an extensive interpretation of this wording would be inadmissible as contrary to the will of the law.

The Court of Reggio Calabria also excludes that the description of the criminalized act can be established through an overall interpretation.

From a second perspective, the referring judge asserts that the lack of objective and specific content in the criminal provision prevents citizens from understanding, in terms of predictability and knowability, the precise scope of the punished offence and consequently infringes the concrete right to defence, guaranteed by Article 24 of the Constitution, in any potential criminal proceedings.

Finally, the vagueness of the illicit act would conflict with the duty established by Article 117, first paragraph, of the Constitution to observe international obligations undertaken, and, in particular, that established by Article 7 of the ECHR, according to which, according to the established interpretation of the European Court of Human Rights, "one of the requirements derived from the wording ‘prescribed by law’ is foreseeability. Consequently, a norm cannot be considered a ‘law’ unless it is formulated with sufficient precision to enable citizens to regulate their conduct; they must be able – if necessary, with appropriate advice – to foresee, to a reasonable degree in the specific circumstances, the consequences that a given act may entail” (citing European Court of Human Rights, Grand Chamber, judgment of 23 February 2017, De Tommaso v. Italy, as well as judgments of 7 June 2012, Centro Europa 7 srl and Di Stefano v. Italy, and 20 May 1999, Rekvènyi v. Hungary, and further judgments of 25 May 1993, Kokkinakis v. Greece, and 26 April 1979, Sunday Times v. United Kingdom).

The referring judge emphasizes that the precedent in the De Tommaso v. Italy case is particularly significant because on that occasion the Strasbourg Court found the criminalization for non-compliance with the "provisions” of "living honestly and respecting the laws” indicated in the preventive measures provided for by Article 75 of Legislative Decree of 6 September 2011, no. 159 (Code of Anti-Mafia Laws and Preventive Measures, as well as new provisions regarding anti-mafia documentation, pursuant to Articles 1 and 2 of Law of 13 August 2010, no. 136) to be contrary to Article 7 of the Convention. This is because such provisions were not sufficiently detailed and therefore proved unforeseeable and unknowable, similarly to what would happen, according to the referring judge, for the challenged contravention offence. Precisely based on the ECtHR decision – recalls the referring order – this Court, with Judgment no. 25 of 2019, declared the unconstitutionality of Article 75, paragraph 2, of Legislative Decree no. 159 of 2011, in so far as it provided for as an offence the violation of obligations and provisions relating to the measure of special supervision, with obligation or prohibition of residence, when consisting in the non-compliance with the provisions of "living honestly” and "respecting the laws”.

2.2.2. – With a second set of issues, the referring Court challenges the combined provisions of Article 20, first paragraph, first sentence, and second paragraph, of Law no. 110 of 1975 for violation of Articles 2 and 3 of the Constitution.

In particular, the imposition, with precautionary-custodial purposes, by the first provision, of the duty to exercise "all diligence” in the custody of arms "negatively and unreasonably affects pursuant to Article 2 of the Constitution the private life of the citizen, the development of their personality, and their daily and overall social formations”: in fact, a "qualitative and quantitative” effort is constantly required to observe an imprecise and, consequently, inesigible duty.

This would also imply the "total unreasonableness” of the entire criminal provision.

2.3. – Finally, the referring judge makes sure to rule out the possibility of a constitutionally oriented interpretation of the combined provisions of Article 20, first paragraph, first sentence, and second paragraph, of Law no. 110 of 1975, which would punish *sic et simpliciter* the failure to observe any type of diligence in the custody of arms.

3. – The President of the Council of Ministers intervened in the proceedings, represented and defended by the State Attorney’s Office, requesting that the issues raised be declared inadmissible or, subsidiarily, unfounded.

3.1. – Firstly, inadmissibility is argued due to lack of relevance. The intervener observes that the referring judge bases the relevance on the state of uncertainty regarding criminal liability linked to the fulfillment of a diligence obligation of doubtful substance, due to the low specificity of the relevant precept, but, on the other hand, already carries out the judgment of established non-compliance by the defendant with the diligence required by him in custody, in relation to the specific and serious situation of his family unit.

Furthermore, according to the Attorney’s Office, there is a lack of precise indication of the direction and content of the corrective intervention sought by the referring judge, who does not undertake to indicate what is "the scope of diligence to satisfy the definiteness of the criminal offence”.

Moreover, inadmissibility is argued due to an erroneous reconstruction of the legal framework. The intervener observes that, according to current jurisprudence, the obligation of diligence in the custody of arms, provided for by Article 20 of Law no. 110 of 1975 – for subjects other than those professionally engaged in matters of arms and explosives – consists in the adoption of precautions that, in specific factual situations, can be required from a person of normal prudence, according to the criterion of *id quod plerumque accidit*, and would therefore not be identifiable as "any abstract diligence,” as asserted by the referring judge.

Finally, the issues complaining about the violation of Articles 2 and 3 of the Constitution are inadmissible due to lack of reasoning, as there is no argumentation supporting them.

3.2. – On the merits, the President of the Council of Ministers asserts the manifest unfoundedness of the first set of issues.

As regards the complaint of infringement of Article 25, second paragraph, of the Constitution, on the one hand, it is argued that the precautionary conduct required is foreseeably determined based on the aforementioned criterion of *id quod plerumque accidit*; on the other hand, it is stressed that, to verify compliance with the principle of specificity of the criminal offence, one must not assess the single descriptive element of the illicit act in isolation, but connect it with the other constituent elements of the offence and with the discipline in which it is inserted.

Regarding the infringement of Article 117, first paragraph, of the Constitution, in relation to Article 7 of the ECHR, the Attorney’s Office, on the one hand, asserts that there is no judgment of the ECtHR that has deemed Article 20 of Law no. 110 of 1975 contrary to the invoked interposed parameter and, on the other hand, denies that the judgment no. 25 of 2019 of this Court, cited by the referring judge, can be relevant, as the non-compliance with "living honestly and respecting the laws” under Article 75, paragraph 2, of Legislative Decree no. 159 of 2011 would have structural characteristics different from the non-compliance with "all diligence” punished by the contravention of which the referring judge doubts.

Considerations in Law

4. – The Ordinary Court of Reggio Calabria, Criminal Section, in a single-judge composition, with the order indicated in the heading, raised questions of constitutional legitimacy concerning the combined provisions of Article 20, first paragraph, first sentence, and second paragraph, of Law no. 110 of 1975, in reference to Articles 2, 3, 24, 25, second paragraph, and 117, first paragraph, of the Constitution, the latter in relation to Article 7 of the ECHR, which punishes with a contravention the subject – other than those professionally engaged in matters of arms or explosives or authorized for the collection or accumulation of arms – who fails to observe the obligation to ensure the custody of such objects "with all due diligence in the interest of public safety”.

In the opinion of the referring judge, the generic nature of the precept, focused on compliance with "all diligence,” would conflict with the principle of certainty and definiteness of criminal law under Article 25, second paragraph, of the Constitution, as well as, consequently, with the right to defence protected by Article 24 of the Constitution, and with the international obligation imposed by Article 7 of the ECHR regarding the definiteness of the criminal offence. Indeed, the failure to comply with "all diligence,” not being sufficiently delimited, would not allow citizens to regulate their conduct based on a foreseeable and knowable precept and to adequately prepare and tailor their defence.

Violation of Articles 2 and 3 of the Constitution is also alleged for the "total unreasonableness” of the entire criminal provision, as imposing "abstractly and constantly” the duty to observe "all diligence” in the custody of arms would result in an imprecise – and therefore inesigible – duty which "negatively and unreasonably affects” the private life of the citizen, "the development of their personality and their daily and overall social formations”.

5. – Preliminarily, the exceptions of inadmissibility raised by the State Attorney’s Office must be examined.

5.1. – Firstly, lack of relevance is alleged, arguing that the referring judge has already formed a judgment (in fact) of established non-compliance with diligence in custody attributable to the defendant. This would lead to the exclusion of the relevance of the issues raised, as they focus precisely on the "non-determination of the act that entails a state of uncertainty (of the liability linked to the fulfillment) of the required diligence which, due to the low specificity of the precept, would appear (or should appear) doubtful”.

In reality, the referring judge merely observes that the specific and serious family situation required a higher standard than that observed by the defendant. Such considerations are limited to referring to the concrete situation, based on an analysis conducted *ex post* in light of the son’s gaining possession of the weapon. Thus, contrary to what is argued by the Attorney’s Office, they in no way crystallize a judgment of established non-compliance with the diligence required by the challenged legislation, the upstream scope of which – according to the referring judge’s assertion – is not adequately defined.

The exception must therefore be dismissed.

5.2. – The Attorney’s Office then argues inadmissibility due to the referring judge’s failure to indicate the direction and content of the desired corrective intervention.

Regarding the indeterminacy of the *petitum* due to the failure to indicate the type of intervention requested, "the constant jurisprudence of the Court affirms that ‘the order referring questions of constitutional legitimacy does not necessarily have to conclude with a provision also containing a *petitum*, it being sufficient that the content and direction of the challenges emerge clearly from the overall tenor of the reasoning’ (Judgment no. 136 of 2022)” (Judgment no. 54 of 2024).

In the present case, even if the referring judge does not advance a precise request – indicating, as the Attorney’s Office would wish, "the scope of diligence to satisfy the definiteness of the criminal offence” – the ambiguity and indeterminacy of the *petitum* likely to constitute grounds for inadmissibility do not appear to be present (Judgments no. 21 of 2020 and no. 239 of 2019), as the question posed by the referring judge, which contests precisely the indeterminacy of the precept, is quite clear.

This exception must also therefore be dismissed.

5.3. – The further exception of inadmissibility for insufficient reasoning regarding the issues relating to Articles 2 and 3 of the Constitution is also destined for a negative outcome.

The complaints are, in fact, entirely lacking in reasoning regarding the requirement of non-manifest unfoundedness, whereas the jurisprudence of this Court requires, in this regard, "that the parameters be evoked in a non-apodictic and generic manner and that the reasons why the violation of the constitutional norms is considered to have occurred be specified, under penalty of manifest inadmissibility of the proposed issues (ex multis, Orders no. 159 of 2021 and no. 261 of 2012)”. Such omissions "irremediably compromise the logical argumentative path forming the basis of the raised challenges, which, according to the constant jurisprudence of this Court, precludes their review, affecting the admissibility of the issues” (Order no. 127 of 2024; in the same vein also, among the latest, Judgments no. 5 of 2025 and no. 110 of 2024).

6. – On the merits, the remaining issues raised are unfounded.

7. – The challenged provisions are part of the discipline concerning common arms and objects capable of causing injury; a discipline whose peculiarity is justified by the specific nature of the instruments considered.

This Court has, on several occasions, emphasized the "intrinsic dangerous characteristics” of such objects and the "extreme gravity of the consequences” linked to their improper use or to their failure to be stored in safe conditions (among the latest, Judgment no. 208 of 2023 and, in a similar sense, Judgment no. 5 of 2023), capable of compromising primary legal assets – human life, public safety, and integrity – which the State has a constitutional duty to protect (Judgment no. 109 of 2019).

Furthermore, the purpose of the discipline regarding the acquisition, carrying, and circulation of arms is to ensure their control and full traceability, as a guarantee of the safety concerning their proper use by the holder, as well as diligent custody in a suitable place, in order to minimise the risk that third parties may gain possession of them for illicit use, even if involuntary (Judgments no. 208 and no. 5 of 2023).

This Court has repeatedly stressed that "carrying a weapon does not constitute an absolute right, but rather an exception to the normal prohibition on carrying arms and that it can only become operative towards persons regarding whom there is perfect and complete certainty concerning the ‘proper use’ of the weapons themselves” (Judgments no. 109 of 2019 and no. 440 of 1993), as also reiterated several times by administrative jurisprudence (Council of State, Third Section, Judgments of 22 July 2024, no. 6565; 22 April 2024, no. 3585; 24 October 2023, no. 9209).

The firearms licence permits the purchase and possession of firearms for particular reasons (self-defence; hunting; sport use, as well as collecting) and is issued, following an articulated procedure, based on "particularly rigorous subjective requirements of reliability” (Judgments no. 5 of 2023 and no. 109 of 2019).

8. – Having established this, the offences of improper custody of arms are currently those provided for by Articles 20, paragraphs one and two, and 20-bis of Law no. 110 of 1975. Furthermore, the last paragraph of Article 38 of Royal Decree of 18 June 1931, no. 773 (Approval of the consolidated text of public security laws) prescribes that "[t]he holder of the arms must ensure that the place of custody offers adequate security guarantees.”

The first sentence of the aforementioned first paragraph of Article 20 addresses the common holder and provides that "[t]he custody of the arms referred to in the preceding Articles 1 and 2 and of explosives must be ensured with all diligence in the interest of public safety”. The second sentence prescribes that "[t]hose professionally engaged in matters of arms or explosives or authorized for the collection or accumulation of arms must adopt and maintain efficient anti-theft defences according to the procedures prescribed by the public security authority.”

The second paragraph of the same Article 20 sanctions the non-compliance with the aforementioned precepts, establishing that "[a]nyone who fails to observe the provisions of the preceding paragraph is punished, if the act does not constitute a more serious offence, by arrest from one to three months or a fine up to one million lire [EUR 516]”.

The last paragraph, introduced by Article 5, paragraph 1, letter m), of Legislative Decree of 26 October 2010, no. 204 (Implementation of Directive 2008/51/EC, amending Directive 91/477/EEC concerning the control of the acquisition and possession of arms), provides that "[w]ith one or more decrees of the Minister of the Interior, to be adopted within six months of the entry into force of this provision, the procedures and deadlines for the custody of arms and parts referred to in the first paragraph shall be determined in relation to the number of arms or parts of arms held, also providing for electronic or passive security systems”. These decrees have not yet been adopted.

The subsequent Article 20-bis, introduced by Article 9, paragraph 1, of Decree-Law of 13 May 1991, no. 152 (Urgent measures on the fight against organized crime and transparency and good administration of administrative activity), converted, with modifications, into Law of 12 July 1991, no. 203, sanctions, in a substantially overlapping manner with the repealed Article 702 of the Criminal Code, active or passive conduct that makes arms and explosives available to persons under eighteen years of age who do not possess an official license, to partially incapable persons, to drug addicts, or to persons inexperienced in handling a weapon. Omissive conduct is regulated by the second paragraph, according to which anyone who "neglects to adopt, in the custody of arms, ammunition and explosives referred to in paragraph 1, the necessary precautions to prevent any of the persons indicated in the same paragraph 1 from easily coming into possession of them” is punished with arrest up to one year or a fine up to two million lire. Both contravention offences are considered serious offences if the conduct concerns war arms or ammunition or explosives legislatively assimilated thereto, as well as clandestine weapons.

9. – The offence of improper custody of arms is an offence of danger, which is perfected by the mere fact that the agent has not adopted the necessary precautions, based on circumstances known or knowable to him with ordinary diligence.

The *ratio* of the aforementioned provisions is to impose the observance of precautions suitable to prevent arms or explosives from coming into the possession of unauthorized subjects in any way; this reflects the particular rigour that the legislator has adopted with the various laws on the matter, with the aim of preventing the uncontrolled circulation of arms and explosives.

The legal interest protected by the challenged Article 20 is "public safety,” in the interest of which the provision expressly requires that the custody of arms be ensured with "all diligence”. This protection is, in reality, instrumental to the protection of other legal interests, such as life and personal integrity, which may be injured or endangered through the use of arms.

The first paragraph of the challenged Article 20 requires the common holder of arms that "[t]he custody […] must be ensured with all diligence in the interest of public safety”.

It is precisely this wording that is challenged by the referring judge, who derives from the assumed generic nature of the precept the violation of the principle of certainty and definiteness, to which the violation of the right to defence – given the impossibility for the defendant, in the absence of clear and precise constituent elements, to develop a specific defensive strategy – and of the principle of foreseeability of criminal liability under Article 7 ECHR are also linked.

10. – The principle under Article 25, second paragraph, of the Constitution consists in the requirement that the legislature describe the criminal offence in a precise and intelligible manner.

On this point, the jurisprudence of this Court has clarified that this principle constitutes "a guarantee against judicial arbitrariness, but also a safeguard of the freedom and security of citizens” (Judgments no. 101 of 2025 and no. 185 of 1992), emphasizing that "[u]nderlying the principles of legality and certainty there are, in fact, two fundamental objectives consisting, ‘on the one hand, in avoiding that, contrary to the principle of the separation of powers and the absolute reservation of law in criminal matters, the judge assumes a creative role, identifying, in place of the legislator, the boundaries between the lawful and the unlawful; and, on the other hand, in guaranteeing free individual self-determination, allowing the recipient of the criminal norm to appreciate a priori the legal and criminal consequences of their conduct’” (Judgment no. 327 of 2008)” (Judgment no. 54 of 2024); more recently, in the same sense, Judgment no. 10 of 2026).

At the same time, while constantly affirming the centrality and non-renounceability of the certainty and definiteness of the criminal precept, this Court has noted that "[e]very normative statement […] presents greater or lesser margins of uncertainty regarding its scope of application, without this leading to its constitutional illegitimacy. The essential task of jurisprudence is to gradually resolve, through the tools of normative exegesis, the interpretative doubts that each provision inevitably raises, in constant confrontation with the concreteness of the cases in which it is applicable; this contributes to making the law more uniform and predictable for citizens” (Judgment no. 110 of 2023).

It has also added that "[t]he use of polysemic expressions, general clauses or elastic terms, or the emergence of interpretative conflicts, do not in themselves denote contradiction with the standard of definiteness, when citizens are nevertheless able to identify with sufficient precision the required conduct (Judgments no. 278 and no. 141 of 2019)” (most recently, Judgment no. 101 of 2025).

Faced with the use of such expressive forms, constitutional jurisprudence has developed precise criteria for measuring compliance with the principle of definiteness. It has thus been affirmed that there can be no violation of this principle when the overall description of the criminalized act allows the judge – taking into account the purposes pursued by the criminalization and the broader regulatory context in which it is situated – to establish the meaning of that element through an interpretive operation not exceeding the ordinary task assigned to him: that is, when that description allows for an assessment of the correspondence of the concrete case to the abstract case, supported by a verifiable hermeneutic foundation; and, correlatively, allows the recipient of the norm to have a sufficiently clear and immediate perception of its prescriptive value, so as to align their conduct with the rules and prohibitions dictated by the law (among the most recent, Judgments no. 101 of 2025, no. 54 of 2024, no. 278, no. 141 and no. 25 of 2019, but also Judgments no. 282 of 2010, no. 327 of 2008 and no. 5 of 2004).

To verify compliance with the principle of definiteness, the overall description of the criminalized act and the context of the discipline in which it is embedded (Judgment no. 25 of 2019) have been valued from time to time, as well as the correlation between the prohibited conduct and the protected interest (Judgment no. 101 of 2025).

A further element constantly recalled by this Court is the jurisprudence developed on the challenged provision: on the one hand, it has been specified that the requirement, protected by the principle of definiteness, of ensuring the recipient of the criminal precept the prior knowledge of what is lawful and what is prohibited "must exist from the first phase of application of the norm, and not only at the moment (which may be much later) when a certain interpretation, which is always susceptible to change, has consolidated in jurisprudence”; on the other hand – it has been added – "[t]his does not preclude, however, that the existence of a constant jurisprudential trend may serve as confirmation of the possibility of identifying, based on an ordinary hermeneutic path, the most precise value of a normative expression that is intrinsically ambiguous, generic, or polysemous” (Judgment no. 327 of 2008).

11. – In light of these guidelines, the alleged indeterminate nature of the precept must be rejected.

11.1. – The challenged provisions adopt the description of the negligent offence as outlined by Article 43 of the Criminal Code, referring to the concept of diligence, logically implied in all criminal offences punishable as negligence. If it is true that for result crimes the occurrence of the result makes it easier to identify the necessary conduct to avoid it, even under the negligent aspect, in danger crimes, such as the one under examination – where the problem of the indeterminacy of the punitive norm arises more significantly –, the selective function, with respect to the scope of the illicit act, of the protected legal interest, constituted – as stated – by the interest of public safety, must be valued.

The conduct required of the non-qualified holder of arms and explosives by the challenged regulation for the custody of arms "with all diligence in the interest of public safety” is, thus, easily perceivable, first and foremost, in light of the clear purpose underlying the discipline of the circulation of arms and explosives, which is – as stated above – to prevent such instruments from coming into the possession of other subjects in any way, frustrating the ultimate goal of preventing their uncontrolled spread and circulation, thereby compromising the protection of other legal interests such as life and personal integrity, which may be injured or endangered through the use of arms.

11.2. – Furthermore, this delineation of the obligation of custody imposed on common holders prescribed by the first period of the first paragraph of Article 20 of Law no. 110 of 1975 is guided by the regulatory context in which it is situated, including, in particular, the discipline under the second period of the same first paragraph, which, for qualified holders (resellers and collectors of arms), expressly requires specific precautions, such as "anti-theft defences according to the procedures prescribed by the public security authority.”

This is complemented by the provision of a different criminal offence under Article 20-bis, which, given the particular vulnerability of the categories of subjects involved, requires even more specific precautions, as clarified also by criminal jurisprudence.

11.3. – A sort of negative delineation and, conversely, a positive definition of the illicit act operated by the Court of Cassation is also relevant here.

On the one hand, the latter has clarified that the "generic duty of diligence in the custody of arms, established by Law no. 110 of 1975, Article 20, paragraph 1, first part, […] must not be confused with the specific one, which requires the adoption of efficient anti-theft defences, established by the second part of the same paragraph 1 of Article 20, only for particular categories of subjects (resellers and collectors of arms), nor with that provided for by Article 20-bis, aimed at preventing arms, ammunition and explosives from coming into the possession of minors, incapable persons, drug addicts or persons inexperienced in handling them (Cass. pen., Section I, no. 1868 of 21/01/2000; Cass. pen., Section I, no. 46265 of 06/10/2004; Cass. pen., Section I, no. 16609 of 11/02/2013; Cass. pen., Section I, 4 November 1999, Digrandi; Cass. pen., Section I, 19 December 1994, Rossi)” (Court of Cassation, First Criminal Section, Judgment of 7 May – 8 July 2019, no. 29849).

On the other hand, the jurisprudence of the Court of Cassation – beyond the comparison with the aforementioned contiguous criminal offences – has carried out a clear and systematic positive delineation of the custody obligation required by the challenged regulation, clarifying that it requires that "precautions be adopted which, in the specific factual situations, can be required from a person of normal prudence according to the criterion of *id quod plerumque accidit*” (among the most recent, Court of Cassation, First Criminal Section, Judgment of 26 September – 21 October 2025, no. 34316; in the same sense, Judgments of 2 May – 28 July 2025, no. 27602; 11 May – 24 September 2021, no. 35453; 11 February – 12 April 2013, no. 16609; 25 January – 2 March 2011, no. 8027).

And it is on the basis of this guiding criterion that the articulated case law regarding the improper custody of arms has been formed, modulating, from time to time, the diligence obligation required of a person of normal prudence based on the specific factual situation.

The physiological differentiation found in case law – far from constituting an index of the alleged indeterminacy of the norms – is precisely due to the need to calibrate the diligence obligation differently based on the "specific factual situations,” as this obligation cannot be defined identically, to exemplify the extreme hypotheses, for the person who possesses a single pistol and lives alone in a hut on a mountain peak, and for the subject, holder of multiple arms or particularly dangerous arms, who lives on the ground floor, together with his family with children and adolescents, in the centre of a small town where leaving the house door open is customary. Between these two, clearly textbook, situations, there lies an undefined series of hypotheses, with respect to which the diligence obligation inevitably assumes a strongly diversified nature, according to an assessment reserved for the trial judge, who is required to provide logical and adequate reasoning in this regard.

Moreover, such an operation of "adaptation” of the precept to the individual concrete case represents, ultimately, precisely a guarantee for the recipient of the precept itself, given the impossibility of laying down general rules capable of encompassing all possible cases and the need to verify the adequacy of precautions on a case-by-case basis.

12. – What has been stated leads to the dismissal of the issues raised concerning Article 25, second paragraph, of the Constitution.

Consequently, the issues relating to Article 24 of the Constitution are also unfounded, since – as already stated in Judgment no. 327 of 2008 – the established absence of a violation of the principle of definiteness also overthrows the further complaints relating to the right to defence, closely linked to it, as well as the issues raised concerning Article 117, first paragraph, of the Constitution, in relation to Article 7 of the ECHR, the foreseeability and knowability of the precept imposed by the criminal norm not being eliminated.

for these reasons

THE CONSTITUTIONAL COURT

1) declares inadmissible the questions of constitutional legitimacy of the combined provisions of Article 20, first paragraph, first sentence, and second paragraph, of Law of 18 April 1975, no. 110 (Provisions supplementing the existing discipline for the control of arms, ammunition, and explosives), raised, in reference to Articles 2 and 3 of the Constitution, by the Ordinary Court of Reggio Calabria, Criminal Section, in a single-judge composition, with the order indicated in the heading;

2) declares unfounded the questions of constitutional legitimacy of the combined provisions of Article 20, first paragraph, first sentence, and second paragraph, of Law no. 110 of 1975, raised, in reference to Articles 24, 25, second paragraph, and 117, first paragraph, of the Constitution, the latter in relation to Article 7 of the European Convention on Human Rights, by the Ordinary Court of Reggio Calabria, Criminal Section, in a single-judge composition, with the order indicated in the heading.

Decided in Rome, at the seat of the Constitutional Court, Palazzo della Consulta, on 12 January 2026.

Signed:

Giovanni AMOROSO, President

Filippo PATRONI GRIFFI, Rapporteur

Valeria EMMA, Chancellor

Filed in the Registry on 20 March 2026

 

The anonymised version is textually consistent with the original