Ex post facto law
| Literal meaning | From a thing done afterwards |
|---|---|
| Pronunciation | ex post FAK-toh |
A law that applies backwards, making an earlier act a crime or increasing its punishment.
Example
A law passed in 2025 makes an act a crime, and a person who did it in 2024 is prosecuted. That is barred.
Case laws
- Kedar Nath Bajoria v. State of West Bengal (1953), Supreme Court: Article 20(1) bars only retrospective criminal laws, not retrospective civil laws.
Statutory link
Article 20(1) of the Constitution of India: no person is convicted for an act that was not an offence when done, or punished more than the law then allowed.
Exam tip
Asked with Article 20(1). Remember that civil laws may be retrospective.
Memory trick
Law made after the act, so no crime.
Key takeaway
Retrospective criminal laws are barred by Article 20(1).
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