Justice
Can a person be punished for something that was not an offence when they did it?
Constitutions answer no, and say so in almost identical words across very different systems: no crime without a prior law, no penalty without prior legal imposition. Brazil states the one permitted exception — retroactivity that benefits the accused.
In short
The principle is usually given in Latin — nullum crimen, nulla poena sine lege — and it contains two demands that are worth separating. The conduct must have been criminal when it was done, and the punishment must have been provided for when it was done.
Why it exists
AnalysisA person can only regulate their conduct against rules that exist. Punishing someone under a rule created afterwards asks them to have complied with something unknowable, and it hands the state a power it could use against anyone by legislating after the fact.
AnalysisThat is why the principle is usually placed among the strongest protections in a constitution rather than in ordinary law: it is a limit on the legislature, and a limit on the legislature has to sit somewhere the legislature cannot reach.
How it works
- Brazil — stated as two prohibitions and one exception
- Article 5º XXXIX: "não há crime sem lei anterior que o defina, nem pena sem prévia cominação legal" — there is no crime without a prior law defining it, and no penalty without prior legal imposition. Article 5º XL then states the exception, and its direction: "a lei penal não retroagirá, salvo para beneficiar o réu" — criminal law shall not be retroactive, save to benefit the accused.
- Germany — stated as a condition on punishing
- Article 103(2) of the Basic Law: "Eine Tat kann nur bestraft werden, wenn die Strafbarkeit gesetzlich bestimmt war, bevor die Tat begangen wurde" — an act may be punished only if its punishability was determined by law before the act was committed. Article 103(3) adds ne bis in idem: no one may be punished more than once for the same act under the general criminal laws.
The principle also does work beyond the criminal law’s edges. Brazil’s Article 5º XXXVI provides that the law shall not impair a vested right, a perfect juridical act or res judicata — the same underlying idea applied to settled legal positions rather than to offences, and the subject of legal certainty.
Common misconceptions
Widely held beliefs that do not match how the system actually operates.
Common belief: Non-retroactivity means the law can never change.
In practice: It means a change cannot reach backwards to make past conduct punishable. Legislatures amend criminal law constantly; what they cannot do is apply the amendment to what was already done.
Common belief: Retroactivity is always forbidden.
In practice: Brazil expressly permits it in one direction: Article 5º XL allows criminal law to be retroactive where it benefits the accused.
Common belief: The principle protects wrongdoers from consequences.
In practice: It requires that the consequence existed in law before the act. Conduct criminal at the time remains punishable; the principle bars punishing conduct that was not.
Common belief: This is a technicality that rarely matters.
In practice: It is the limit that prevents a state from legislating against a person after identifying them. Both constitutions here place it among fundamental rights rather than in ordinary procedural law.
How this varies between jurisdictions
A required section on every guide. Arrangements differ between countries, and we say how.
The two texts here express the same principle with different emphasis, and the difference is instructive.
- Brazil states it as two prohibitions — no crime, no penalty — and then names the exception.
- Germany states it as a single condition on the power to punish, and adds ne bis in idem beside it.
International instruments state the principle for states party to them. The Universal Declaration of Human Rights carries the declared principle that no one shall be held guilty of a penal offence on account of an act which did not constitute a penal offence under national or international law at the time it was committed. As always on this site, that establishes an international standard and not the law of any particular state.
Rights and accountability
AnalysisFor a reader, the practical significance is that the question "was this lawful?" always has a date attached. Whether conduct was an offence is answered by the law as it stood when the conduct occurred, not by the law as it stands when the question is asked.
What we could not establish
- Two constitutions were read from primary text for this page. The principle appears widely, but this page states it only for the systems whose text was read, and describes no country’s case law on how the principle is applied at the margins.
- How courts treat changes in sentencing law, in limitation periods, or in procedural rules is a body of jurisprudence that was not researched and is not described.
Where to go next
Related: limits on public power, legal certainty, and Brazil.
Related topics
- What limits does law place on what the state may do to a person?
Four recurring limits appear in constitutional text: an act must have a legal basis that existed beforehand, the person must be heard, the decision must be capable of review, and some things may not be done at all.
- Why does it matter that people can know where they stand in law?
Because a rule you cannot find, cannot understand, or that can be changed against you afterwards cannot guide anything. Constitutions protect settled positions directly — vested rights, completed acts, and decisions that have become final.
- What actually stops a government from doing as it likes?
Constitutions answer this in text, not in sentiment. Germany binds the executive and the judiciary to law and opens the courts against public authority; South Africa requires administrative action to be lawful, reasonable and procedurally fair; Brazil forbids any law excluding a rights claim from the courts.
Where this connects
Institutions: Constitutional court.
Sources
Grundgesetz für die Bundesrepublik Deutschland — Art. 3, 19, 20 und 103 (German original text)
Bundesministerium der Justiz / Bundesamt für Justiz (Gesetze im Internet) · Legislation · link verified 2026-08-26
The authoritative German text of four Basic Law articles, each fetched at its own address on gesetze-im-internet.de and read directly. Supports, verbatim: Art. 3(1) "Alle Menschen sind vor dem Gesetz gleich" — all persons are equal before the law. Art. 19(4) "Wird jemand durch die öffentliche Gewalt in seinen Rechten verletzt, so steht ihm der Rechtsweg offen" — where a person's rights are violated by public authority, recourse to the courts is open to them, with the ordinary courts available where no other jurisdiction is established. Art. 20(2), that state authority is exercised through specific organs of legislation, executive power and adjudication; and Art. 20(3) "Die Gesetzgebung ist an die verfassungsmäßige Ordnung, die vollziehende Gewalt und die Rechtsprechung sind an Gesetz und Recht gebunden" — legislation is bound by the constitutional order, and the executive and the judiciary are bound by law and justice. Art. 103(1) "Vor Gericht hat jedermann Anspruch auf rechtliches Gehör" — before a court everyone is entitled to a hearing in accordance with law; Art. 103(2) "Eine Tat kann nur bestraft werden, wenn die Strafbarkeit gesetzlich bestimmt war, bevor die Tat begangen wurde" — an act may be punished only if its punishability was determined by law before the act was committed; Art. 103(3) ne bis in idem under the general criminal laws. Cited for equality before the law, the guarantee of recourse against public authority, the binding of the executive and judiciary to law, the right to be heard, and the legality and non-retroactivity of criminal punishment. It establishes no proportionality test — the German proportionality doctrine is judicial rather than textual and was not researched.
Constituição da República Federativa do Brasil de 1988
Presidência da República — Casa Civil (Planalto) · Legislation · 1988-10-05 · link verified 2026-07-25
The authoritative Portuguese text, read in full. THE backbone of the Brazil pages. Supports: the federation of the Union, the States, the Federal District and the Municipalities, 'todos autônomos' (Art. 18; Art. 1); separation of powers (Art. 2); the criminal-justice guarantees of Art. 5 — devido processo legal (LIV), contraditório e ampla defesa (LV), presumption of innocence 'ninguém será considerado culpado até o trânsito em julgado de sentença penal condenatória' (LVII), and habeas corpus (LXVIII); that penal and procedural law are the EXCLUSIVE (privativa) competence of the Union (Art. 22, I) while direito penitenciário is CONCURRENT (Art. 24, I) and the States hold the reserved/residual competences (Art. 25 §1); public security through the six órgãos of Art. 144 (I polícia federal; II rodoviária federal; III ferroviária federal; IV polícias civis; V polícias militares e corpos de bombeiros militares; VI polícias penais, added by EC 104/2019), with the polícias civis 'dirigidas por delegados de polícia de carreira' exercising 'as funções de polícia judiciária e a apuração de infrações penais, exceto as militares' (§4), the polícias militares holding 'a polícia ostensiva e a preservação da ordem pública' (§5), and both subordinate to the Governors (§6); the Judiciary organs of Art. 92 (STF, CNJ, STJ, TST, TRFs/Juízes Federais, and the labour, electoral, military and state courts), the STF as guardian of the Constitution (Art. 102), the CNJ (Art. 103-B) and state justice (Art. 125); the Ministério Público as 'instituição permanente, essencial à função jurisdicional do Estado' defending 'a ordem jurídica, o regime democrático e os interesses sociais e individuais indisponíveis', with autonomy and the principles of unidade, indivisibilidade e independência funcional (Art. 127), its structure MPU (MPF/MPT/MPM/MPDFT) + MPE (Art. 128), its functions including promoting 'privativamente, a ação penal pública' (Art. 129 I) and the inquérito civil / ação civil pública for interesses difusos e coletivos (Art. 129 III), and the CNMP (Art. 130-A); and that the Union organizes and maintains the Judiciary, Ministério Público and police of the Federal District (Art. 21, XIII–XIV). The Portuguese text alone has legal effect. WAVE 12 ADDITION, further clauses of Art. 5 read directly from the same Planalto text: XXXV a lei não excluirá da apreciação do Poder Judiciário lesão ou ameaça a direito; XXXVI the law shall not impair a vested right, a perfect juridical act or res judicata; XXXVII não haverá juízo ou tribunal de exceção; XXXIX não há crime sem lei anterior que o defina, nem pena sem prévia cominação legal; XL a lei penal não retroagirá, salvo para beneficiar o réu; LVI evidence obtained by unlawful means is inadmissible in the process; LXXV the State shall indemnify a person convicted by judicial error and one held beyond the term fixed in the sentence; LXXVIII reasonable duration of proceedings and the means guaranteeing the speed of their handling, in the judicial and administrative spheres. WAVE 14 ADDITION, further provisions read directly from the same Planalto text: Art. 5º LXXIV “o Estado prestará assistência jurídica integral e gratuita aos que comprovarem insuficiência de recursos”; Art. 5º LXXVI that civil birth registration and the death certificate are free, in the form of the law, for the recognisedly poor; Art. 5º LXXVII that actions of habeas corpus and habeas data are free, as are, in the form of the law, the acts necessary to the exercise of citizenship; Art. 103-B § 4º that the Conselho Nacional de Justiça has competence for “o controle da atuação administrativa e financeira do Poder Judiciário e do cumprimento dos deveres funcionais dos juízes”, including safeguarding the autonomy of the Judiciary and issuing regulatory acts (I), reviewing the legality of administrative acts of members or organs of the Judiciary and annulling, revising or setting a period for compliance (II), and receiving complaints against members or organs of the Judiciary including its auxiliary services and delegated notarial and registry services, taking over disciplinary proceedings in course and ordering removal, availability or retirement and applying other administrative sanctions (III); Art. 133 “O advogado é indispensável à administração da justiça, sendo inviolável por seus atos e manifestações no exercício da profissão, nos limites da lei”; and Art. 134 in its current wording, that the Defensoria Pública is a permanent institution essential to the jurisdictional function of the State, incumbent on it, as an expression and instrument of the democratic regime, fundamentally to provide legal guidance, the promotion of human rights and the defence, in all degrees, judicial and extrajudicial, of the individual and collective rights of the needy. WAVE 20 ADDITION. Read from the same Planalto text. Brazil states its emergency architecture as a closed system: two regimes, an exhaustive list of measures for each, and an express preservation of liability afterwards. Supports Constituição de 1988, Art. 136, caput: “Art. 136. O Presidente da República pode, ouvidos o Conselho da República e o Conselho de Defesa Nacional, decretar estado de defesa para preservar ou prontamente restabelecer, em locais restritos e determinados, a ordem pública ou a paz social ameaçadas por grave e iminente instabilidade institucional ou atingidas por calamidades de grandes proporções na natureza.”. Supports Constituição de 1988, Art. 136 § 2º, added after adversarial review found this platform quoting it from a record that did not carry it, and re-verified against the Planalto text: “§ 2º O tempo de duração do estado de defesa não será superior a trinta dias, podendo ser prorrogado uma vez, por igual período, se persistirem as razões que justificaram a sua decretação.” Supports Constituição de 1988, Art. 136 §1º, I–II: “I - restrições aos direitos de: a) reunião, ainda que exercida no seio das associações; b) sigilo de correspondência; c) sigilo de comunicação telegráfica e telefônica; II - ocupação e uso temporário de bens e serviços públicos, na hipótese de calamidade pública, respondendo a União pelos danos e custos decorrentes.”. Supports Constituição de 1988, Art. 136 §3º, I–IV: “§ 3º Na vigência do estado de defesa: I - a prisão por crime contra o Estado, determinada pelo executor da medida, será por este comunicada imediatamente ao juiz competente, que a relaxará, se não for legal, facultado ao preso requerer exame de corpo de delito à autoridade policial; II - a comunicação será acompanhada de declaração, pela autoridade, do estado físico e mental do detido no momento de sua autuação; III - a prisão ou detenção de qualquer pessoa não poderá ser superior a dez dias, salvo quando autorizada pelo Poder Judiciário; IV - é vedada a incomunicabilidade do preso.”. Supports Constituição de 1988, Art. 136 §§4º–7º: “§ 4º Decretado o estado de defesa ou sua prorrogação, o Presidente da República, dentro de vinte e quatro horas, submeterá o ato com a respectiva justificação ao Congresso Nacional, que decidirá por maioria absoluta. § 5º Se o Congresso Nacional estiver em recesso, será convocado, extraordinariamente, no prazo de cinco dias. § 6º O Congresso Nacional apreciará o decreto dentro de dez dias contados de seu recebimento, devendo continuar funcionando enquanto vigorar o estado de defesa. § 7º Rejeitado o decreto, cessa imediatamente o estado de defesa.”. Supports Constituição de 1988, Art. 138, caput: “Art. 138. O decreto do estado de sítio indicará sua duração, as normas necessárias a sua execução e as garantias constitucionais que ficarão suspensas, e, depois de publicado, o Presidente da República designará o executor das medidas específicas e as áreas abrangidas.”. Supports Constituição de 1988, Art. 139: “Art. 139. Na vigência do estado de sítio decretado com fundamento no art. 137, I, só poderão ser tomadas contra as pessoas as seguintes medidas: I - obrigação de permanência em localidade determinada; II - detenção em edifício não destinado a acusados ou condenados por crimes comuns; III - restrições relativas à inviolabilidade da correspondência, ao sigilo das comunicações, à prestação de informações e à liberdade de imprensa, radiodifusão e televisão, na forma da lei; IV - suspensão da liberdade de reunião; V - busca e apreensão em domicílio; VI - intervenção nas empresas de serviços públicos; VII - requisição de bens. Parágrafo único. Não se inclui nas restrições do inciso III a difusão de pronunciamentos de parlamentares efetuados em suas Casas Legislativas, desde que liberada pela respectiva Mesa.”. Supports Constituição de 1988, Art. 141 and parágrafo único: “Art. 141. Cessado o estado de defesa ou o estado de sítio, cessarão também seus efeitos, sem prejuízo da responsabilidade pelos ilícitos cometidos por seus executores ou agentes. Parágrafo único. Logo que cesse o estado de defesa ou o estado de sítio, as medidas aplicadas em sua vigência serão relatadas pelo Presidente da República, em mensagem ao Congresso Nacional, com especificação e justificação das providências adotadas, com relação nominal dos atingidos e indicação das restrições aplicadas.”. Supports Constituição de 1988, Art. 60 §§1º and 4º: “§ 1º A Constituição não poderá ser emendada na vigência de intervenção federal, de estado de defesa ou de estado de sítio. […] § 4º Não será objeto de deliberação a proposta de emenda tendente a abolir: I - a forma federativa de Estado; II - o voto direto, secreto, universal e periódico; III - a separação dos Poderes; IV - os direitos e garantias individuais.”. Supports Constituição de 1988, Art. 142, caput and §1º: “Art. 142. As Forças Armadas, constituídas pela Marinha, pelo Exército e pela Aeronáutica, são instituições nacionais permanentes e regulares, organizadas com base na hierarquia e na disciplina, sob a autoridade suprema do Presidente da República, e destinam-se à defesa da Pátria, à garantia dos poderes constitucionais e, por iniciativa de qualquer destes, da lei e da ordem. § 1º Lei complementar estabelecerá as normas gerais a serem adotadas na organização, no preparo e no emprego das Forças Armadas.”. Cited for the closed lists of permitted measures, the immediate judicial communication of an arrest, the congressional role, the express preservation of liability for unlawful acts after the regime ends, and the bar on amending the Constitution while one is in force. It records no declaration of either regime and supports no claim about any other country.WAVE 21 ADDITION. Article 5 read incisum by incisum from the same Planalto consolidated text. Supports the caput, and specifically its rights-holder scope: “Todos são iguais perante a lei, sem distinção de qualquer natureza, garantindo-se aos brasileiros e aos estrangeiros residentes no País a inviolabilidade do direito à vida, à liberdade, à igualdade, à segurança e à propriedade, nos termos seguintes”. Supports Art. 5º X: “são invioláveis a intimidade, a vida privada, a honra e a imagem das pessoas, assegurado o direito a indenização pelo dano material ou moral decorrente de sua violação”. Supports Art. 5º XI: “a casa é asilo inviolável do indivíduo, ninguém nela podendo penetrar sem consentimento do morador, salvo em caso de flagrante delito ou desastre, ou para prestar socorro, ou, durante o dia, por determinação judicial” — note that judicial authorisation is textually confined to daytime, which is the narrowest such qualifier found in this wave. Supports Art. 5º XII: “é inviolável o sigilo da correspondência e das comunicações telegráficas, de dados e das comunicações telefônicas, salvo, no último caso, por ordem judicial, nas hipóteses e na forma que a lei estabelecer para fins de investigação criminal ou instrução processual penal” — the exception reaches the LAST-NAMED category only, requires a judicial order, and is confined to criminal investigation or criminal procedural instruction. Supports Art. 5º LIV (“ninguém será privado da liberdade ou de seus bens sem o devido processo legal”), LV (contraditório and ampla defesa in judicial and administrative proceedings), LVI (“são inadmissíveis, no processo, as provas obtidas por meios ilícitos”) and LVII. Supports Art. 5º LXI: “ninguém será preso senão em flagrante delito ou por ordem escrita e fundamentada de autoridade judiciária competente, salvo nos casos de transgressão militar ou crime propriamente militar, definidos em lei”. Supports LXII (arrest and place of custody communicated immediately to the competent judge and to the family or a person indicated). Supports LXIII: “o preso será informado de seus direitos, entre os quais o de permanecer calado, sendo-lhe assegurada a assistência da família e de advogado” — a constitutional notification duty coupled with a silence right, and worded for “o preso”. Supports LXIV, LXV (“a prisão ilegal será imediatamente relaxada pela autoridade judiciária”) and LXVI. Supports § 1º (“As normas definidoras dos direitos e garantias fundamentais têm aplicação imediata”), § 2º (rights expressed in the Constitution do not exclude others deriving from the regime and principles it adopts, or from international treaties to which Brazil is party) and § 3º (“Os tratados e convenções internacionais sobre direitos humanos que forem aprovados, em cada Casa do Congresso Nacional, em dois turnos, por três quintos dos votos dos respectivos membros, serão equivalentes às emendas constitucionais”, added by Emenda Constitucional nº 45 de 2004). VERIFIED NEGATIVE: Article 5 contains no general limitation clause of the Canadian, South African, Kenyan or Swiss kind; limits appear inside individual incisos. Constitutional text only — no decision of the Supremo Tribunal Federal, no statute, nothing about any other country.
Universal Declaration of Human Rights
United Nations · International organisation · 1948-12-10 · link verified 2026-07-23
Supports the existence and wording of the declared principles of equality before the law (Art. 7), the right to an effective remedy (Art. 8), the right to a fair and public hearing by an independent and impartial tribunal (Art. 10), and the presumption of innocence (Art. 11). A declaration, not a treaty: it does not establish binding obligations, and it does not support any claim about how a particular state implements these principles.
United Nations · International organisation · 1966 · link verified 2026-07-23
Authentic treaty text as registered in the UN Treaty Series; registered ex officio 23 March 1976. Supports the fair-trial guarantees of Article 14, including the right to a competent, independent and impartial tribunal established by law, and the presumption of innocence (Art. 14(2)). Binding only on states party to it; does not support claims about states that have not ratified, nor about how any individual state applies it. WAVE 19 ADDITION, read from the same authentic treaty text in the UN Treaty Series PDF, text-extracted locally. Supports Article 14(5) in full: "Everyone convicted of a crime shall have the right to his conviction and sentence being reviewed by a higher tribunal according to law." The qualifier "according to law" is part of the provision and is load-bearing: the right is to review as the law of the state provides, not to appeal without limit or by any chosen route. Supports Article 14(6): where a person has by a FINAL decision been convicted of a criminal offence and the conviction has subsequently been reversed or the person pardoned on the ground that a new or newly discovered fact shows conclusively that there has been a miscarriage of justice, the person who has suffered punishment as a result shall be compensated according to law, unless it is proved that the non-disclosure of the unknown fact in time is wholly or partly attributable to that person. Supports Article 14(3)(g), that no one shall be compelled to testify against himself or to confess guilt, and Article 14(4), that the procedure for juvenile persons shall take account of their age and the desirability of promoting their rehabilitation. WAVE 20 ADDITION. PROVENANCE, stated precisely because this record's url is a different copy: the Article 4 material below was read on 2026-08-26 from OHCHR's official PDF of the Covenant at https://www.ohchr.org/sites/default/files/ccpr.pdf. The United Nations Treaty Series copy at this record's url timed out repeatedly this session and was not re-read, so nothing in this addition rests on it. Article 4 is the derogation clause, and its four cumulative conditions are the point. Supports ICCPR Art. 4(1): “1. In time of public emergency which threatens the life of the nation and the existence of which is officially proclaimed, the States Parties to the present Covenant may take measures derogating from their obligations under the present Covenant to the extent strictly required by the exigencies of the situation, provided that such measures are not inconsistent with their other obligations under international law and do not involve discrimination solely on the ground of race, colour, sex, language, religion or social origin.”. Supports ICCPR Art. 4(2), read with Arts. 6, 7, 8, 11, 15, 16 and 18 as printed in the same document: “2. No derogation from articles 6, 7, 8 (paragraphs 1 and 2), 11, 15, 16 and 18 may be made under this provision.”. Supports ICCPR Art. 4(3): “3. Any State Party to the present Covenant availing itself of the right of derogation shall immediately inform the other States Parties to the present Covenant, through the intermediary of the Secretary-General of the United Nations, of the provisions from which it has derogated and of the reasons by which it was actuated. A further communication shall be made, through the same intermediary, on the date on which it terminates such derogation.”. The Covenant binds States Parties to it. It is NOT evidence of any particular state's domestic law, and no country claim on this platform rests on it. It designates no organ to proclaim an emergency, assigns no role to any national legislature, and creates no civil-protection institution. The Human Rights Committee's interpretation of this article is cited separately and attributed to the Committee.WAVE 21 ADDITION. Read from the same United Nations Treaty Series PDF, text-extracted and searched. Supports Art. 9(1)-(4), and specifically that the Covenant polices ARBITRARINESS rather than closing a list of grounds: “Everyone has the right to liberty and security of person. No one shall be subjected to arbitrary arrest or detention. No one shall be deprived of his liberty except on such grounds and in accordance with such procedure as are established by law”; with 9(2) (informed at the time of arrest of the reasons and promptly of any charges), 9(3) (brought promptly before a judge or other officer authorised by law to exercise judicial power; it shall not be the general rule that persons awaiting trial shall be detained in custody) and 9(4) (entitlement to take proceedings before a court which decides without delay on the lawfulness of the detention). Supports Art. 14(1): “All persons shall be equal before the courts and tribunals”, with the right to a fair and public hearing by a competent, independent and impartial tribunal established by law, the closed grounds on which press and public may be excluded, and the rule that judgment shall be made public except where the interest of juvenile persons otherwise requires or the proceedings concern matrimonial disputes or the guardianship of children. Supports Art. 14(3)(e) (“To examine, or have examined, the witnesses against him and to obtain the attendance and examination of witnesses on his behalf under the same conditions as witnesses against him”), 14(3)(f) (free assistance of an interpreter) and 14(3)(g) (“Not to be compelled to testify against himself or to confess guilt” — note that the Covenant adds the confession limb, which the European Convention text does not contain). Supports Art. 14(5). VERIFIED NEGATIVES from exhaustive search of the Covenant text: “proportion” occurs zero times, “equality of arms” zero times, and “remain silent” zero times. This is treaty text binding states party to it; it is not evidence of any state's domestic law, and the corpus invariant forbidding a treaty from standing in for a country applies to it.