Ex Post Facto Laws Under Article 20(1)



The ‘ex-post-facto’ is simply a law that is retrospective; that is law made after the doing of the thing to which it relates and retroacting upon it. Such laws are generally deemed unfair, because in the nature of the case, the person, or persons, involved in the behavior to which such a law relates, can had no notice, when the behavior took place, of such an after made law which applies to it.

The unfairness varies however, from cases of the doing of behavior things in reliance on legal technicalities; in other cases, supervening unforeseen events may give rise to equities which wipe any unfairness out; and the public welfare sometimes demands that legislation be passed which, in some measures disregards individuals strict antecedent rights.


Constitution of India has some provisions and protections for the rights of people who has already committed any crime or for the people whose trial is pending which is given under article 20 and article 22. At the time of constituting draft for article 20 constitutional advisor B.N. Rao pointed out that in every progressive country’s constitution one can find these three protections:

  1. Protection from Ex post facto laws
  2. Protection from Double jeopardy
  3. Protection from self-incrimination

Legislature can make any kind of laws it may be of prospective nature or of retrospective nature. Prospective law means which is applicable to the future or one which provides for, and regulate the future acts of men and does not interfere in any way with what has past. Whereas, retrospective laws deals with which that is to take effect, in point of time, before it was passed.

Article 20(1) – Protection against Ex Post Facto Law

Ex post facto is a Latin term meaning ‘from a thing done afterward’. It imposes penalties retrospectively, i.e. on acts already done and increases the penalty for such acts. The American Constitution also contains a similar provisions, prohibiting ex post facto law both by the central and the state legislative.

Protection from ex post facto laws basically close legislative from making retrospective laws in criminal matters. In other words, if any person have committed any offence today then he/she will be governed by the laws which are applicable by that day. If by certain time law changes he/she will not be affected by those laws. If certain act which is legal today may not be legal after some years because of due consequences. Therefore, person who has committed that legal act during the time which it was legal shall not be affected when it became illegal after years. Under the American law the prohibition applies even in respect of trial.

The guarantee in American constitution is thus wider than that under the Indian constitution. The protection of clause (1) of article 20 cannot be claimed in case of preventive detention or demanding security from a person. The prohibition is just or conviction and sentence only and not for prosecution and trial under a retrospective law. So, a trial under a procedure different from what it was at the time of the commission of the offence or by a special court constituted after the commission of the offence ipso facto be held unconstitutional.

Further 20(1) deals with penalty, which says if he/she has committed any offence today and it has some penalty he/she cannot be punished greater than that which he might have been subjected to, at the time of the commission of the offence.

Case Laws:

  1. Kedar Nath v. State of West Bengal (AIR 1953 SC 404) in 1947 a person committed an offence and in 1947, it was law that for that offence a person shall be either punished with imprisonment or with fine or both. The act was amended in 1949 which enhanced the punishment for the same offence by an additional fine equivalent to the amount of money procured by the accused through the offence. The Supreme Court held that enhanced punishment could not be applicable to the act committed by the accused in 1947, hence set aside the additional fine imposed by the amendment act.
  2. Mohan Lal v. State of Rajasthan (AIR 2015 SC 2098) the Supreme Court held accused guilty under section 18 of NDPS act because he was in possession of the banned substance on date of enforcement of the act. He had both the ‘corpus’ and ‘animus’ which were necessary for possession under the law. Article 20(1) was held to be not applicable because the action of possession was not punishable with retrospective effect. The punishment was for possession of the prohibited article on or after a particular date on the enactment of the statute.
  3. Ratanlal v. State of Punjab (AIR 1965 444) a boy of 16 years of age was convicted for committing an offence of house trespass and outraging the modesty of a girl aged 7 years. The magistrate sentenced him for 6 months rigorous imprisonment and also imposed fine. After the judgment of magistrate the Probation of Offenders Act, 1958 came into force. It provided that a person below 21 years of age should not ordinarily be sentenced to imprisonment. The Supreme Court by a majority of 2 to 1 held that the rule of beneficial interpretation required that ex post facto law could be applied to reduce the punishment,. So an ex post facto law which is beneficial to the accused is not prohibited by clause (1) of article 20.

Therefore, the rule of beneficial construction requires that ex post facto law should be applied to mitigate the rigorous (reducing the sentence) of the previous law or the same subject. Such a law is not affected by article 20 (1). The principle is based on sound reason and common sense.

Author: Nishchal Kukade,
Dr. Babahaseb Ambedkar College of Law, Nagpur Final Year Student

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