Article 20 of the Constitution Ex Post Facto Law, Double Jeopardy & Self-Incrimination
Article 20 is the Fundamental Right that shields an accused person from the excesses of the State's penal power. It sits in Part III of the Constitution and carries three distinct guarantees in three clauses — protection against retrospective criminal law, against double punishment, and against compelled self-incrimination. Along with Article 21, it is one of only two Fundamental Rights that cannot be suspended even during a National Emergency.
What Article 20 Protects
Article 20 is titled "Protection in respect of conviction for offences". It restrains all three organs of the State at once — the Legislature cannot criminalise past conduct, the Executive cannot extract self-incriminating testimony by compulsion, and the Judiciary cannot punish the same offence twice.
Who can claim Article 20?
- Available to citizens and non-citizens (foreigners) alike — the text says "no person", not "no citizen".
- Available to legal persons such as companies and corporations, in addition to natural persons.
- Cannot be suspended during an Emergency. The proviso to Article 359(1), inserted by the 44th Constitutional Amendment Act, 1978, bars any Presidential order suspending the enforcement of Articles 20 and 21.
During the 1975 Emergency, the Supreme Court in ADM Jabalpur v. Shivkant Shukla (1976) held that even the right to move a court for enforcement of Article 21 stood suspended. The 44th Amendment responded by placing Articles 20 and 21 permanently beyond the reach of Article 359. This is one of the most frequently asked Prelims points on the entire Emergency chapter — and the reason Article 20 is described as non-derogable.
Article 20(1) — Protection Against Ex Post Facto Law
No person shall be convicted of any offence except for violation of a law in force at the time of the commission of the act charged as an offence, nor be subjected to a penalty greater than that which might have been inflicted under the law in force at the time of the commission of the offence. — Article 20(1), Constitution of India
Prospective and retrospective law
Every law operates in one of two directions. A prospective law governs conduct occurring after it comes into force. A retrospective law reaches backwards and attaches new legal consequences to a transaction that has already concluded.
An ex post facto law is the criminal species of retrospective law — legislation passed after an act, which either makes that act an offence for the first time, or increases the punishment for it.
The two limbs of Article 20(1)
What Article 20(1) does and does not cover
- Convict a person under a law enacted after the act
- Impose a punishment heavier than the one in force at the time of the offence
- Treat a law as "in force" merely because a later statute deems it to be retrospectively in force
- The trial itself. Article 20(1) bars conviction and sentence, not prosecution or trial
- Changes in procedure. A trial under a new procedure, or before a differently constituted court, is not unconstitutional
- Beneficial retrospectivity. A law reducing punishment may be applied retrospectively
- Civil and tax liability. Retrospective civil obligations and tax levies are outside Article 20(1)
- Preventive detention. It is not a "conviction for an offence"
Leading cases on Article 20(1)
| Case | Holding |
|---|---|
| Kedar Nath Bajoria v. State of West Bengal (1953) | Where the legislature declares an act to be a criminal offence, or enhances the punishment for an existing offence, such a declaration operates prospectively only. Article 20(1) prohibits the conviction and the sentence, not the trial. |
| Rao Shiv Bahadur Singh v. State of Vindhya Pradesh (1953) | The expression "law in force" means a law factually in operation at the time of the offence — not a law subsequently brought into force with retrospective effect. The Court also held that an accused has no fundamental right to be tried by a particular court or a particular procedure. |
| Rattan Lal v. State of Punjab (1964) | The recognised exception: where the subsequent law reduces the punishment or is otherwise beneficial to the accused, it may be applied retrospectively. Ex post facto operation is barred only when it works to the accused's detriment. |
| Mohan Lal v. State of Rajasthan (2015) | Arising under the NDPS Act, 1985. Reaffirmed that what Article 20 prohibits is only conviction or sentence under an ex post facto law, not the trial. A trial under a different procedure, or by a differently competent court, cannot ipso facto be held unconstitutional. |
The NDPS case is Mohan Lal v. State of Rajasthan (2015) — the accused was the appellant. It is frequently written the other way round as "State of Rajasthan v. Mohan Lal", which is incorrect. Getting case names in the right order matters in Mains, where an examiner reads the citation as a signal of how carefully the candidate has studied.
Article 20(2) — Protection Against Double Jeopardy
No person shall be prosecuted and punished for the same offence more than once. — Article 20(2), Constitution of India
The clause embodies the maxim nemo debet bis vexari pro una et eadem causa — no one ought to be vexed twice for the same cause. Once a person has been prosecuted and punished for an offence, the State cannot subject him to a second round of prosecution and punishment for that same offence.
Ingredients — all three must be satisfied
- The person must have been accused of an offence.
- There must have been a prosecution for that offence — before a court or a judicial tribunal.
- That prosecution must have resulted in punishment.
Article 20(2) protects against being "prosecuted and punished" — the conjunction is cumulative. Both conditions must have been met before the bar operates. The consequence is significant: Article 20(2) covers only autrefois convict (previously convicted), not autrefois acquit (previously acquitted). A person acquitted at the first trial cannot invoke Article 20(2) as a constitutional bar to a second trial. This makes the Indian provision narrower than the American Fifth Amendment, which covers acquittals as well.
Where the acquitted person finds protection: statute, not the Constitution
The gap left by Article 20(2) is filled by the ordinary law of criminal procedure. Section 337 of the Bharatiya Nagarik Suraksha Sanhita, 2023 — corresponding to Section 300 of the CrPC, 1973 — provides that a person once tried by a court of competent jurisdiction and convicted or acquitted shall not be liable to be tried again for the same offence, nor on the same facts for any other offence for which a different charge might have been made.
| Point of comparison | Article 20(2), Constitution | Section 337, BNSS 2023 |
|---|---|---|
| Status | Fundamental Right | Statutory right |
| Trigger | Previous prosecution and punishment | Previous trial ending in conviction or acquittal |
| Covers acquittal? | No | Yes |
| Bars a second… | Punishment | Trial itself |
| Exceptions | Judicially evolved (e.g. departmental proceedings, distinct offences) | Expressly provided — distinct offence with State Government's consent; new consequences arising later; court not competent at the first trial |
Leading cases on Article 20(2)
| Case | Holding |
|---|---|
| Maqbool Hussain v. State of Bombay (1953) | The appellant brought gold into India without declaring it; the customs authorities confiscated it. He was later prosecuted under the Foreign Exchange Regulation Act. The Court held that the Sea Customs Authority is neither a court nor a judicial tribunal, so the confiscation was not a "prosecution and punishment". The subsequent criminal prosecution was therefore not barred by Article 20(2). |
| S. A. Venkataraman v. Union of India (1954) | A departmental enquiry under the Public Servants (Inquiries) Act is not a "prosecution", and dismissal from service is not "punishment" within Article 20(2). A subsequent criminal prosecution for the same conduct is permissible. The clause addresses judicial punishment only. |
| General principle on distinct offences | Article 20(2) bars a second prosecution for the same offence. Where the same set of facts constitutes two distinct offences with different ingredients, prosecution for the second is not barred — even though the two offences share a common element. |
The correct citation is Maqbool Hussain v. State of Bombay — Maqbool Hussain was the appellant challenging the State. Writing it as "State of Bombay v. Maqbool Hussain" reverses the parties.
Article 20(3) — Right Against Self-Incrimination
No person accused of any offence shall be compelled to be a witness against himself. — Article 20(3), Constitution of India
This is the constitutional foundation of the presumption of innocence in Indian criminal procedure. The burden of proving guilt rests on the prosecution, and the accused cannot be made an instrument of his own conviction.
Ingredients — all three must be satisfied
- The person must be "accused of an offence" — there must be a formal accusation against him at the relevant time.
- There must be compulsion to be a witness — protection extends to both physical and mental compulsion.
- The compelled testimony must be against himself, that is, self-incriminating in nature.
What counts as "being a witness"?
This is the analytical heart of Article 20(3), and it turns on a distinction the Supreme Court drew in Kathi Kalu Oghad: "to be a witness" is not the same as "to furnish evidence". The clause protects the personal knowledge of the accused — the contents of his mind. It does not protect material that merely exists on or about his body.
- Compelled oral testimony conveying personal knowledge
- Compelled written statements based on personal knowledge
- Narcoanalysis — involuntary administration
- Polygraph (lie-detector) test — involuntary administration
- Brain Electrical Activation Profile (BEAP) / brain mapping — involuntary administration
- Thumb impressions and fingerprints
- Specimen signature and handwriting samples
- Blood, semen, hair and other bodily samples
- Voice samples (on a Magistrate's order)
- Search and seizure of documents from premises
- Information given voluntarily, without compulsion
Leading cases on Article 20(3)
| Case | Holding |
|---|---|
| M. P. Sharma v. Satish Chandra (1954) | "To be a witness" includes oral, documentary and testimonial evidence. However, a search and seizure of documents from a person's premises does not amount to compelled testimony and is not hit by Article 20(3). (Note: this decision's separate observation that the Constitution recognises no right to privacy was overruled in K. S. Puttaswamy v. Union of India, 2017.) |
| Narayanlal Bansilal v. Maneck Phiroz Mistry (1961) | A formal accusation must exist before Article 20(3) can be invoked. The protection is not available at the stage of a general investigation or inquiry where no person stands formally accused. |
| State of Bombay v. Kathi Kalu Oghad (1961) | An eleven-judge Bench narrowed M. P. Sharma. "To be a witness" means imparting personal knowledge, and is not the same as "furnishing evidence". Compelling an accused to give specimen handwriting, signatures, thumb or finger impressions does not violate Article 20(3), because these are identification material, not communication of knowledge. |
| Nandini Satpathy v. P. L. Dani (1978) | The appellant, a former Chief Minister of Odisha, was summoned to a Vigilance police station under the Prevention of Corruption Act, 1947, and handed a long written questionnaire. The Supreme Court held that Article 20(3)'s purpose is to protect the accused from unwarranted police compulsion, that the protection extends to the investigation stage and not merely to the trial, and that it covers a suspect summoned for questioning, not only a person already formally charged. |
| Selvi v. State of Karnataka (2010) | A landmark three-judge ruling: the involuntary administration of narcoanalysis, polygraph and BEAP (brain-mapping) tests violates Article 20(3) as well as Article 21, because these techniques extract knowledge from the subject's mind that he has not chosen to disclose. The Court distinguished them from medical examination and bodily samples, which remain permissible. |
| Ritesh Sinha v. State of Uttar Pradesh (2019) | A three-judge Bench held that a Judicial Magistrate may order an accused to give a voice sample for the purposes of investigation, and that doing so does not violate Article 20(3) — applying the Kathi Kalu Oghad logic that a voice sample is identification material rather than communication of personal knowledge. |
The reason narcoanalysis fails the test while a blood sample passes it is not the invasiveness of the procedure — it is whose mind supplies the content. A blood sample exists independently of what the accused thinks. A narcoanalysis answer exists only because the technique reached into the accused's memory and drew it out without his volition. Selvi also anchored this in mental privacy under Article 21, which is why the judgment is cited in the privacy jurisprudence that culminated in Puttaswamy (2017).
Article 20 at a Glance — Mind Map
Prelims Traps to Guard Against
- Article 20 uses "person", not "citizen". Foreigners and companies can claim it.
- Only Articles 20 and 21 survive an Emergency. The proviso to Article 359(1), inserted by the 44th Amendment (1978), bars their suspension. Article 19 is not in this category.
- Article 20(1) bars conviction and sentence, not trial. A retrospective change in procedure is constitutional.
- Reduction of punishment can operate retrospectively. Article 20(1) protects the accused; it is not a bar on measures that benefit him (Rattan Lal).
- Article 20(2) says "prosecuted and punished". It does not protect a previously acquitted person — that protection comes from Section 337 BNSS, a statutory right.
- Departmental proceedings are not "prosecution". A civil servant can face both a departmental enquiry and a criminal trial for the same conduct (Venkataraman).
- Customs confiscation is not double jeopardy. The authority is not a court or judicial tribunal (Maqbool Hussain).
- Thumb impressions, handwriting samples and voice samples are outside Article 20(3); narcoanalysis, polygraph and brain mapping are inside it. The dividing line is personal knowledge.
- Kathi Kalu Oghad was an eleven-judge Bench — one of the largest Benches in Indian constitutional history, and it narrowed M. P. Sharma.
Mains Angle
Question (GS-II, 15 marks, 250 words): "Article 20 of the Constitution restrains the legislature, the executive and the judiciary simultaneously." Examine this statement, and assess whether the protection against double jeopardy under Article 20(2) is adequate in its present form.
Structure the answer around three pivots: the tri-organ restraint — Article 20(1) on retrospective legislation, Article 20(3) on executive and police compulsion, Article 20(2) on repeated judicial punishment; the adequacy question — Article 20(2)'s cumulative "prosecuted and punished" requirement excludes autrefois acquit, a gap covered only statutorily by Section 337 BNSS and therefore amendable by ordinary legislation, unlike the American Fifth Amendment; and the evolving frontier — Selvi (2010) extending Article 20(3) to mental privacy, read with Puttaswamy (2017), against Ritesh Sinha (2019) permitting compelled voice samples. Conclude on the balance between investigative efficiency and the dignity of the accused.
Key Takeaways
- Article 20 guarantees three protections to an accused — against ex post facto law (clause 1), double jeopardy (clause 2) and self-incrimination (clause 3) — and restrains the legislature, executive and judiciary respectively.
- It is available to citizens, foreigners and legal persons, and along with Article 21 it cannot be suspended during a National Emergency by virtue of the proviso to Article 359(1) inserted by the 44th Amendment, 1978.
- Article 20(1) bars conviction and enhanced punishment under retrospective criminal law, but not the trial or a change of procedure — and a law reducing punishment may apply retrospectively (Rattan Lal, 1964).
- Article 20(2) requires that the person was prosecuted and punished before a court or judicial tribunal; it does not cover prior acquittal, and departmental or customs proceedings do not trigger it (Venkataraman; Maqbool Hussain).
- The wider protection covering both conviction and acquittal is statutory — Section 337 of the BNSS, 2023, corresponding to Section 300 of the CrPC, 1973.
- Article 20(3) protects personal knowledge, not identification material. Kathi Kalu Oghad (1961) permits handwriting and thumb impressions; Selvi (2010) bars involuntary narcoanalysis, polygraph and brain mapping; Nandini Satpathy (1978) extends the protection to the investigation stage.
