## Facts

- Multiple criminal matters were consolidated to address the constitutionality of administering narcoanalysis, polygraph examinations, and Brain Electrical Activation Profile (BEAP) tests during investigations.
- Investigating agencies sought to use these techniques on accused persons, suspects, and sometimes witnesses to obtain information for investigative leads.
- In several matters, Magistrates or courts authorized, or investigating agencies proposed, the use of these techniques without the subject’s consent.
- The techniques involved (i) drug-induced questioning (narcoanalysis), (ii) measuring physiological responses associated with deception (polygraph), and (iii) recording brain responses to stimuli to infer familiarity with case-related facts (BEAP).
- The challengers argued compelled use violated the constitutional privilege against self-incrimination and the right to personal liberty, including mental privacy and bodily integrity.

## Issues

1. Whether involuntary administration of narcoanalysis, polygraph, and BEAP constitutes “testimonial compulsion” barred by the constitutional privilege against self-incrimination.
2. Whether the privilege applies at the investigative stage and protects not only formally accused persons but also suspects and witnesses facing exposure to criminal liability.
3. Whether compelled use of these techniques violates personal liberty protections, including mental privacy, bodily integrity, and freedom from coercive or degrading treatment.
4. Whether test results or information obtained through these techniques is admissible, and whether derivative material discovered through disclosures may be used under ordinary evidentiary rules.
5. Whether such techniques can be justified as routine medical examination or as a permissible investigative aid under criminal procedure law.

## Decision

- The Court held that involuntary administration of narcoanalysis, polygraph examination, and BEAP is unconstitutional.
- Compelled use violates the privilege against self-incrimination because these techniques extract or reveal the contents of a person’s mind and therefore amount to testimonial compulsion.
- The protection was not confined to trial testimony; it applies at the investigative stage and extends to persons who may be compelled to provide incriminating personal knowledge, including suspects and witnesses in appropriate circumstances.
- Forced use also violated personal liberty guarantees, including mental privacy and bodily integrity, and could not be justified solely by investigative utility.
- Results of tests administered through compulsion were held inadmissible as evidence.
- The Court allowed only limited use of independently obtained derivative material (such as physical evidence discovered) where admissible under ordinary evidentiary rules, and did not treat that possibility as authorizing compelled testing.
- The Court permitted use of these techniques only with informed, voluntary consent and subject to strict procedural safeguards and medical and ethical guidelines.

## Legal Principles

- The privilege against self-incrimination prohibits compelled extraction of testimonial material, including compelled disclosures of memories, knowledge, or thoughts, even when sought during investigation.
- Compulsion to provide testimonial material is constitutionally distinct from compelled collection of non-testimonial physical evidence (e.g., identification or bodily samples).
- Personal liberty protects bodily integrity and mental privacy; intrusive investigative techniques that access mental processes without consent are presumptively unreasonable.
- Compelled results from narcoanalysis, polygraph, and BEAP are inadmissible; any admissible derivative “discovery” is limited to independent material obtained in a manner consistent with evidentiary rules and does not validate forced testing.
- Voluntary administration requires informed consent and compliance with strict safeguards to reduce coercion and protect dignity and autonomy.

## Conclusion

The Court barred the State from forcibly subjecting individuals to narcoanalysis, polygraph examinations, or BEAP tests, holding such compulsion violates protections against self-incrimination and personal liberty, renders compelled results inadmissible, and permits use only on informed consent under stringent safeguards.


Selvi v. State of Karnataka, (2010) 7 S.C.C. 263 (India)