The recent news of a political leader having to give voice samples to the Central Bureau of Investigation (CBI) in connection with the 1984 anti-Sikh riots, has brought to light the importance of voice samples in criminal investigations. These samples serve as important tools in corroborating evidence and identifying suspects.
Collection and Comparison of Voice Samples
Investigating agencies need court permission to collect a person’s voice sample. This collection is done in an echo-proof room to ensure noise-free and controlled conditions. The subject is asked to speak a specific word from a statement that’s already part of the evidence.
For comparison purposes, an anonymous voice sample is usually matched with a suspect list containing five individuals. In situations where the speaker is known, both voice samples are compared for verification. International phonetic alphabets are used during recording to simplify analysis.
Voice Sampling Procedure in India
In Indian forensic labs, the semi-automatic spectrographic method is used for voice sampling. After analyzing the collected samples, a final report is submitted to the investigating agency specifying whether the results are positive or negative. However, some countries use automatic methods where a likelihood ratio of the voice samples is established, leading to increased efficiency.
Potential Drawbacks
Despite its advantages, inaccuracies can occur in voice sample collection. Factors like effects of medicines or ailments like a cold can alter a person’s voice, affecting the accuracy of the sample. The reliability of the voice sample also largely depends on the technique applied by the expert and how the court interprets it.
Legal Implications of Collecting Voice Samples
In 2013, the Indian Supreme Court considered the legality of collecting voice samples. It questioned whether this process would infringe upon the fundamental right against self-incrimination or even the right to privacy. It was established that the term “such other tests” mentioned in Section 53 (1) of the Code of Criminal Procedure includes the collection of voice samples.
The Right to Privacy
The right to privacy is safeguarded as an essential part of the right to life and personal liberty under Article 21 and the freedoms guaranteed by Part III of the Constitution. According to a landmark decision in K.S. Puttaswamy v. Union of India in 2017, the right to privacy is a basic and non-transferable right that pertains to all information about a person, including their choices.
Previous Instances of Voice Sample Collection
In the past, voice samples have been collected in several cases. For instance, in February 2021, a Special Court under the Narcotic Drugs and Psychotropic Substances Act (NDPS) approved the Narcotics Control Bureau (NCB)’s petition to collect voice samples from 33 accused in a drug case associated with actor Sushant Singh Rajput’s death.
Voice Recognition as Biometric Identification
Besides fingerprint scanning, biometric identification can also include iris scanning, retinal scanning, and voice recognition. Biometric verification is a unique identifier that can distinguish a person based on one or more characteristics. This approach is not new; the oldest form of biometric verification is fingerprinting. But today, other processes like iris scans, voice recognition, and retinal scanning are also used for biometric identification.
