The Central Bureau of Investigation (CBI) in India conducting a polygraph test (commonly known as a lie detector test) on an accused individual signifies an important step in a criminal investigation. A polygraph test is used to determine whether a person is being truthful or deceptive in their responses during questioning. Here's a detailed overview of what this means and the implications:
### **1. What is a Polygraph Test?**
- **Purpose and Method:** A polygraph test measures physiological responses such as heart rate, blood pressure, respiratory rate, and skin conductivity while a person answers questions. The idea is that deceptive answers will produce physiological responses that differ from those when a person is truthful. The test is administered by a trained polygraph examiner who interprets the results.
- **Usage in Investigations:** In India, the polygraph test is sometimes used by law enforcement agencies, including the CBI, during investigations to corroborate or challenge the statements made by suspects or witnesses. However, it is important to note that the results of a polygraph test are not considered conclusive evidence in court but can aid in guiding the investigation.
### **2. Legal and Ethical Considerations**
- **Voluntary Consent:** In India, conducting a polygraph test requires the voluntary consent of the individual being tested. The person must be fully informed about the nature of the test and its implications, and consent is typically documented in writing.
- **Supreme Court Guidelines:** The use of polygraph tests is governed by guidelines set by the Supreme Court of India. In a landmark ruling in 2010 (Selvi & Ors vs State of Karnataka), the Supreme Court held that polygraph tests, along with other techniques like narco-analysis and brain mapping, cannot be conducted without the consent of the accused. Additionally, the results of such tests cannot be used as evidence in court, but any information or leads obtained during the test may be investigated further.
### **3. Implications for the Investigation**
- **Corroboration of Evidence:** The polygraph test can help investigators verify the credibility of the accused's statements. If the test indicates deception, it may lead the CBI to scrutinize the accused's statements more closely and seek additional evidence.
- **Guiding the Investigation:** The results of the polygraph test can provide valuable leads or confirm suspicions that investigators might have. This can help in narrowing down the focus of the investigation or identifying inconsistencies in the accused's version of events.
- **Not Admissible in Court:** It is crucial to understand that while a polygraph test can be a useful tool in the investigative process, its results are not admissible as evidence in a court of law. This is because the reliability of polygraph testing is still debated among experts, and there are concerns about its accuracy.
### **4. Ethical Concerns and Criticisms**
- **Accuracy and Reliability:** The accuracy of polygraph tests has been a subject of debate. While proponents argue that the test is a useful tool for detecting deception, critics point out that physiological responses can be influenced by various factors unrelated to lying, such as anxiety, fear, or medical conditions.
- **Potential for Coercion:** There is also concern about the potential for coercion, where individuals might feel pressured to undergo the test even if they are uncomfortable with it. This is why the Supreme Court has emphasized the need for voluntary consent.
- **Human Rights Perspective:** From a human rights perspective, there are arguments against the use of polygraph tests, especially in situations where they might be used to exert psychological pressure on the accused. Ensuring that the test is conducted ethically and with full respect for the individual's rights is paramount.
### **5. Conclusion**
The CBI's decision to conduct a polygraph test on an accused individual is a strategic move in their investigative process. While the test itself is not conclusive and cannot be used as direct evidence in court, it can play a crucial role in guiding the investigation and verifying the information provided by the accused. The use of such tests must be carefully balanced with legal, ethical, and human rights considerations to ensure that the investigation is both thorough and just.
