Source: The Hindu 

Introduction 

In August, the CBI carried out a second round of polygraph tests on seven people linked to the rape and murder of a resident doctor from R.G. Kar Medical College in Kolkata. This included the college's former principal, several doctors who dined with the victim, and two civic police volunteers, with one being the main suspect. The additional tests were prompted by inconsistencies in the principal’s responses, and the CBI has been investigating the case since 13 August, after a Calcutta High Court order. 

What is Deception Detection Tests (DDT)? 

Deception detection tests (DDTs) are scientific procedures that detect probable deception during interrogation. There are three main types of DDTs: 

• Polygraph Tests: 
  • Operate on the assumption that specific physiological responses occur when a person is lying 
  • Measure variables like blood pressure, galvanic skin response, breathing, and pulse rate 
  • Use instruments like cardio-cuffs or sensitive electrodes attached to the suspect 
  • Assign numerical values to physiological responses to determine truthfulness 
• Narco-Analysis: 
  • Involves injecting a drug called sodium pentothal into the accused 
  • Induces a hypnotic or sedated state 
  • Based on the assumption that a subject in this state is less inhibited and more likely to reveal information 
  • Often referred to as a "truth serum" 
• Brain Mapping: 
  • Measures neural activity, specifically brainwaves 
  • Uses electrodes attached to the face and neck 
  • Based on the principle that the brain generates distinctive brainwaves when exposed to familiar stimuli 

How have Indian Courts Evolved in Their Stance on Deception Detection Tests Over Time? 

• Madras High Court in Dinesh Dalmia v. State (2006): 
  • Directed investigating agencies to complete investigations within a reasonable time 
  • Suggested scientific investigation methods (like DDTs) may be necessary if the accused doesn't cooperate during custodial interrogation 
• Gujarat High Court in Santokben Sharma bhai Jadeja v. State of Gujarat (2007): 
  • Held that conducting DDTs is part of the investigation 
  • Ruled that consent of the accused is not required for these tests 
• Delhi High Court in Shailender Sharma v. State (2008): 
  • Upheld the constitutionality of involuntary administration of narco-analysis 
  • Stated it's necessary to balance society's needs with proper investigation 
  • Noted that self-incriminatory statements made during narco-analysis cannot be used by prosecution 
• Supreme Court in Selvi v. State of Karnataka (2010): 
  • Ruled that DDTs cannot be performed without consent 
  • Raised concerns about violation of 'Right against self-incrimination' (Article 20(3)) and 'Right against cruel, inhuman or degrading treatment' (interpreted from Article 21) 
  • Allowed admission of information or material subsequently discovered with the help of voluntary test results, in accordance with Section 27 of the Evidence Act, 1872 
• Supreme Court in Sidhu Yadav @ Siddharth v. State of NCT of Delhi (2017): 
  • Dismissed a petition by an individual volunteering for narco-analysis 
  • Stated that investigation falls in the domain of police, and the court cannot order the mode and method of the probe 
• Supreme Court in 2020 (Hathras case): 
  • Reaffirmed the 2010 judgment, holding that involuntary administration of DDT is an intrusion into a person's mental privacy 

What is the Legal Admissibility of the Polygraph Test? 

• The polygraphy test, along with other methods like narco-analysis and brain-mapping, is utilized by police to facilitate investigations while avoiding physical violence. 
• These methods mainly rely on extracting information from the accused, potentially incriminating them. 
• According to Article 21(3) of the Indian Constitution,1950 individuals cannot be compelled to testify against themselves, making polygraphy test results inadmissible as evidence in court. 
• The National Human Rights Commission (NHRC) has issued guidelines to conduct polygraphy tests in accordance with Article 21, safeguarding personal liberty and privacy rights. 
• Prior to these guidelines, tests were often coercive and violated individual liberties. Despite the guidelines, some agencies may not fully adhere to NHRC recommendations. 
• The questions about the accuracy of polygraphy tests, as fear or panic during interrogation may lead to unreliable results. 
• This poses the risk of wrongful punishment for innocent individuals who may falsely incriminate themselves under pressure. 

How did Indian Courts' Stance on Deception Detection Tests (DDTs) Evolve Before 2010? 

• Indian courts were strongly in favor of using DDTs, often deeming the consent of the accused as irrelevant for administering these tests. 
• Landmark Cases: 
  • Rojo George v. Deputy Superintendent of Police (2006) - Kerala High Court: 
    • Noted that crime techniques had become "very sophisticated and modern" 
    • Deemed scientific tests (DDTs) essential for effective investigations 
    • Stated that when conducted under strict expert supervision, these tests do not violate fundamental rights of citizens 
  • Dinesh Dalmia v. State (2006) - Madras High Court: 
    • Observed that reliance on DDTs by investigating agencies did not constitute "testimonial compulsion" 
    • Presented DDTs as "scientific methods of investigation" 
    • Portrayed DDTs as a safer alternative to custodial violence often used to extract information 
  • Sh. Shailender Sharma v. State & Another (2008) - Delhi High Court: 
    • Asserted the need to balance thorough and proper investigation against individual rights 
    • Stated that narco-analysis tests "do not suffer from any constitutional infirmity" 
    • Described DDTs as a "step in aid of investigation" 
    • Allowed the administration of narco-analysis tests 
• Rationale for supporting DDTs: 
  • Courts recognized the evolving nature of criminal techniques 
  • DDTs were seen as necessary tools for effective modern investigations 
  • These tests were considered preferable to potentially violent interrogation methods 
  • Courts aimed to balance societal needs for thorough investigations with individual rights 
• Legal Perspective: 
  • Courts generally did not view DDTs as violating fundamental rights when properly administered 
  • The use of DDTs was not considered a form of compelled testimony 
  • There was a tendency to prioritize investigative needs over concerns about individual consent 
  • This situation contrasts sharply with the post-2010 legal landscape, where the Supreme Court's judgment in Selvi vs. State of Karnataka significantly altered the approach to DDTs, emphasizing consent and constitutional protections. 

How Did Indian Courts' Stance on Deception Detection Tests (DDTs) Evolve After 2010? 

• Landmark Case: Selvi vs. State of Karnataka (2010) - Supreme Court 
  • Consent Requirement: 
    • DDTs should not be administered without the consent of the accused 
    • This aligns with the fundamental right against self-incrimination (Article 20(3) of the Constitution) 
  • Right to Privacy: 
    • The right to make a statement or remain silent is integral to the right to privacy 
    • Compelling an individual to make a statement violates Article 21 of the Constitution 
  • Reliability Concerns: 
    • The Court noted a lack of empirical evidence supporting the reliability of DDTs 
    • Cautioned against regarding test results as "confessions" 
  • Admissibility of Evidence: 
    • Results of DDTs cannot be directly admitted as evidence 
    • However, any information or material subsequently discovered with the help of voluntarily administered test results can be admitted in court 
  • Procedural Safeguards: 
    • Individuals volunteering for DDTs must have access to a lawyer 
    • Subjects must be informed of the physical, emotional, and legal implications of the test 
    • Consent must be formally recorded before a judicial magistrate 
    • Guidelines set by the National Human Rights Commission (2000) for administering these tests must be strictly followed 
• Implications: 
  • Significant shift from pre-2010 stance, prioritizing individual rights and consent 
  • Increased protection of privacy and against self-incrimination 
  • More stringent requirements for the use and admissibility of DDT results 
  • Greater emphasis on voluntary participation and informed consent 
  • Recognition of potential unreliability of DDTs in investigative processes 

Why are Lie Detector Tests Still Used in India Despite Supreme Court Cautions? 

• The Supreme Court has warned against using lie detector tests, they are still commonly used in India.  
• This is different from many other countries where these tests are becoming less popular. 
•  In recent years, these tests have been used in some big cases in India, like: 
  • The 2020 gang rape case in Hathras 
  • The 2012 Sheena Bora disappearance case 
  • The 2022 Shraddha Walker murder case 
• Jinee Lokaneeta, who wrote a book about this topic, says these tests are very invasive.  
  • She questions whether people in police custody can really give free and informed consent for these tests.  
  • Lokaneeta also mentions cases where people were forced to take these tests and were physically abused. 
  • This happened in the 2007 Mecca Masjid blasts case and the 2006 Mumbai blasts case.  
  • In these instances, the tests were used to make people give false confessions. 
• Rebecca John, a senior lawyer, says these lie detector tests pretend to be scientific, but they're not.  
  • She also points out a problem: if someone refuses to take these tests, it's often used against them in court.  
  • The prosecution might say this refusal means the person is guilty or hiding something. John says this is unfair because people have a constitutional right to refuse these tests. 

Conclusion 

Despite a 2010 Supreme Court ruling emphasizing that deception detection tests (DDTs) should only be used with consent and cannot be admitted as direct evidence, these tests remain widely used in India. The Court stressed that such tests should respect individual rights and privacy, but concerns persist about their invasive nature and reliability. Critics argue that the consent given under police pressure may not be truly voluntary, and refusal to undergo these tests can be unfairly used against individuals in court.