4 min readMumbaiFeb 9, 2023 01:13 PM IST
First published on: Feb 9, 2023 at 01:13 PM IST
A 2021 rape-murder case saw the Mumbai police using a gait analysis test as a forensic tool for the first time. On the intervening night of September 9 and 10, 2021, a woman was found in an injured state in the Saki Naka area of Mumbai. She was rushed to a civic-run hospital with severe injuries and succumbed to them the next day. Her medical examination had revealed that she was raped and assaulted with a sharp object inserted in her private parts, causing fatal injuries. The police began a search for the perpetrator after the woman’s identity was established through her family and other witnesses.
Among the evidence gathered by the police in narrowing down on the accused was CCTV footage from the spot. While the person seen near the spot of the incident was not clearly visible in the footage, the police in its investigation relied on gait analysis to corroborate his identity. The accused, Mohan Chauhan, was arrested on the basis of multiple pieces of evidence, including an eyewitness who established that the accused knew the victim and was seen near the spot at the time.
This was the first time that a gait analysis test was used in the city as a forensic tool.
The CCTV footage was submitted to the state Forensic Science Laboratory in Kalina where experts analysed the gait of the accused. Following Chauhan’s arrest, the police also recorded his gait which was also submitted to the experts for comparison to corroborate the CCTV footage.
During the trial, a scientific officer from the laboratory explained gait analysis as a process where the gait of a person, that is the ‘walking manner’ is compared with footage from a CCTV camera where a suspect is seen walking. The court was informed that a sample video was taken of the suspect’s walking movement, at the same angle and light condition and covering the same distance as seen in the CCTV. The official explained that the sample video and the CCTV footage were compared software and analysed frame by frame.
The analysis of Chauhan’s gait had revealed that the hairline, forehead and shoulders “were found similar” to the male person in the reference photographs and the CCTV footage. The expert said that the body structure and walking style appeared similar but also said that certain comparative features could not be extracted due to night vision, distance and height of the camera. The court relied on the evidence along with other witnesses in establishing the identity of the accused and convicting him.
Chauhan was found guilty under charges including murder and rape and was sentenced to death in June 2022.
Gait analysis is still at an initial stage in criminal trials in the country and opinions are divided on its accuracy and reliability. The prosecution while relying on it had said that while there have been no precedents on gait analysis being used as evidence in Maharashtra, it cannot be a ground to discard it.
In a gait analysis, the 'walking manner' of the accused is compared to CCTV footage. (Representational Image) 
Share
