Polygraph Test Overview and Procedure

Polygraph Test Overview

• A polygraph test measures physiological responses to assess deception, monitoring heart rate, blood pressure, respiration, and skin conductivity.
• Physiological indicators include heart rate and blood pressure changes, respiratory rate patterns, and galvanic skin response (GSR) reflecting moisture levels in the skin.
• Sensors are connected to the chest, fingertips, and arm to capture responses during the test.

Procedure

• Baseline questions establish normal physiological responses before asking control and relevant questions.
• The analysis compares physiological changes during relevant questions to detect potential deception.

Recent Context

• The Central Bureau of Investigation (CBI) recently used polygraph tests on accused individuals in the Kolkata Rape and Murder Case.

Legal Framework

• Article 20(3) of the Indian Constitution protects individuals from self-incrimination, requiring consent for polygraph tests.
• Article 21 raises concerns regarding violations of the right to life and privacy linked to the mental stress associated with polygraph tests.
• Key judicial rulings include:
  • Selvi vs. State of Karnataka (2010): Stipulates polygraph tests must be voluntary and based on informed consent.
  • D.K. Basu vs. State of West Bengal (1997): Highlights that involuntary tests may infringe on rights to life and privacy.

Admissibility in Court

• Under the Indian Evidence Act, 1871, results from polygraph tests are not admissible as courtroom evidence.

Human Rights Guidelines

• National Human Rights Commission Guidelines (1999) set standards for consent and procedural requirements to ensure polygraph tests comply with human rights.