Electronic Evidence | Nodal Officers Must Be Examined To Prove CDRs; Gait Analysis Inadmissible If Source CCTV Is Corrupted: Supreme Court

"A comparison of two unreliable pieces of evidence cannot produce a reliable piece of evidence. Re-enacting the occurrence certainly leads to revelation of facts within personal knowledge and would amount to becoming a witness against himself," Supreme Court, in a significant ruling dated May 19, 2026, held that Call Detail Records (CDRs) cannot be proved merely by a police officer producing them without examining the nodal officers of telecom companies.

A bench of Justices M. M. Sundresh and Satish Chandra Sharma observed that strict compliance with Section 65-B of the Evidence Act and the maintenance of an unbroken chain of custody are non-negotiable for electronic evidence. The Court further ruled that while gait analysis is a recognized scientific technique, it cannot be relied upon if the underlying CCTV footage is mishandled or the source hard disk is corrupted.

The case arose from the broad daylight murder of Dr. Subbiah, a reputed Chennai surgeon, in 2013 over a prolonged land dispute involving nine accused persons. While the Trial Court had awarded death sentences to seven of the accused, the Madras High Court later acquitted all of them, prompting the State of Tamil Nadu to appeal. The Supreme Court eventually set aside the acquittal, restoring the conviction of all nine accused but sentencing them to life imprisonment.

The primary questions before the Court were whether CDRs can be admitted in evidence without examining the telecom company’s nodal officer who generated them. The Court was also called upon to determine the admissibility of a gait analysis report derived from re-enactment videos and CCTV footage with a broken chain of custody. Furthermore, it examined whether compelling an accused to re-enact a crime scene violates the protection against self-incrimination under Article 20(3) of the Constitution.

Strict Proof Required For Electronic Records

The Court expressed agreement with the High Court’s decision to reject the CDRs (Ex. P112 to Ex. P145) because they were exhibited by a Sub-Inspector rather than the competent nodal officers. The bench noted that the police official merely received the records via email and was not the person in lawful control of the system that produced the records. The prosecution’s failure to examine the authors of these electronic documents was deemed a fatal procedural lapse.

"The prosecution ought to have simultaneously examined the nodal officers as well, so as to prove that the CDRs were indeed generated and sent by the telecom companies. The failure to examine the nodal officers raises credible questions regarding the chain of custody."

CDRs In Editable Format Cannot Inspire Confidence

The bench highlighted that the CDRs were produced in an Excel format, which is inherently editable and susceptible to manipulation. It held that the prosecution failed to place the original emails on record, further weakening the authenticity of the electronic evidence. The Court emphasized that for a document to be proved under Section 65-B, it must be supported by the certificate of a competent person who had control over the device that generated the record.

Distinction Between Re-enactment And Personal Testimony

Addressing the controversial use of crime scene re-enactment, the Court observed that a directed demonstration of physical attributes, like walking, does not per se amount to being a witness against oneself. However, if an accused is led into demonstrating incriminating acts from their own personal knowledge, such evidence is hit by Article 20(3) and Sections 25 and 26 of the Evidence Act. The Court cautioned that re-enactment is not a substantive piece of evidence but merely a corroborative tool.

"If the accused is somehow led into demonstrating the incriminating acts committed by him from his own knowledge, the same would amount to testimonial compulsion and would be squarely hit by Section 25 and 26 of Evidence Act."

Gait Analysis Depends On Integrity Of Source Footage

The Court rejected the gait analysis report prepared by a private lab because the original CCTV footage from which it was derived was mishandled. The hard disk was seized after a month’s delay, and the Digital Video Recorder (DVR) was scrapped before it could be examined. The bench found it "dangerous" to place reliance on scientific reports when the source hard disk was found to be corrupted during the trial.

"The gait analysis report must be based on a comparison of two admissible and reliable pieces of evidence. A comparison of two unreliable pieces of evidence cannot produce a reliable piece of evidence."

Procedural Lapses In Identification Vitiate Scientific Evidence

The bench noted that a police constable had kept the CCTV footage in a pen drive for over a month without it being sent to the Court or examined by experts immediately. This distorted chain of custody created reasonable doubt regarding the genuineness of the video played in the Trial Court. Consequently, the Court held that the gait analysis report, which relied on this truncated and unverified footage, had no evidentiary value.

Conviction Restored Based On Direct Oral Evidence

Despite rejecting the electronic and scientific evidence, the Supreme Court restored the conviction of all accused based on the consistent testimonies of eye-witnesses and the approver. The Court held that the High Court erred in adopting an "artificial standard" to reject public witnesses as chance witnesses. It observed that the motive for the murder—a land dispute worth crores—was clearly established and fortified the prosecution's case.

"The job of an Appellate Court is not to automatically enter into reappreciation of evidence by force of habit. As long as the view taken by the Trial Court is a legally possible view, mere availability of an alternate view is not enough to reverse such view."

The Court concluded that the High Court had replaced a legally plausible view of the Trial Court with its own subjective assessment. While the State did not press for the death penalty, the Supreme Court sentenced the convicts to life imprisonment. It also granted the parents of the main conspirators (A1 and A2) the liberty to seek a Governor's pardon under Article 161 of the Constitution, citing their limited role and advanced age.

Date of Decision: May 19, 2026