Step 1: Understanding the Concept:
The question describes the facts leading to the landmark Supreme Court case of Selvi & Ors. vs. State of Karnataka (2010). It asks for the final holding of the Supreme Court regarding the constitutionality of compulsory administration of investigative techniques like polygraphy (lie-detector test), brain-mapping (P300 test), and narcoanalysis (truth serum).
Step 2: Detailed Explanation:
The Supreme Court, in its comprehensive judgment, analyzed these techniques in the light of fundamental rights. The key findings were:
1. Violation of Article 20(3) (Right against Self-Incrimination): The Court held that forcing an individual to undergo these tests amounts to 'testimonial compulsion'. The results obtained are in the nature of testimony or communication from the accused's mind, and if this is done without consent, it violates the right against self-incrimination, which states that "No person accused of any offence shall be compelled to be a witness against himself."
2. Violation of Article 21 (Right to Life and Personal Liberty): The Court also held that these tests are an intrusion into the mental privacy of an individual, which is an integral part of the right to personal liberty under Article 21. Forcing someone to speak or reveal information against their will is a violation of their dignity and autonomy.
The Court did clarify that these tests can be administered if the accused voluntarily consents to them, after being fully informed of the consequences and having access to a lawyer. However, compulsory administration is unconstitutional.
Article 20(1) deals with ex post facto laws, and Article 14 deals with the right to equality, which were not the primary grounds for the decision.
Step 3: Final Answer:
The Supreme Court held that the compulsory administration of these tests violates both Article 20(3) and Article 21 of the Constitution.