Ketan Agarwal case: What’s gait analysis that can help crack the Lohagad Fort murder?

Ketan Agarwal murder case has taken the country by storm. New angles and fresh details emerging every passing day are only making this case progressively more horrifying and unsettling.

As investigators aggressively unfold the probe, forensic gait analysis, a key scientific tool, is now at the centre of the wealthy 26-year-old Pune realtor murder investigation. According to officials, the analysis could help identify the accused who attempted to hide his identity in CCTV footage.

On Monday (June 29), the court extended the police custody of prime accused Siya Goyal and co-accused Chetan Chaudhary, Goyal's alleged lover, in the case till July 3. The court granted custody after accepting the prosecution’s argument that a forensic examination of the accused’s walking pattern is still pending. This analysis by officials will match Chaudhary’s gait (walking pattern) with CCTV footage near the crime scene at Lohagad Fort.

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Ketan died after being pushed from a height into a gorge at Lohagad Fort, Pune, by his fiancée Goyal and Chaudhary on June 18. Initially, Goyal thought she could hoodwink the law-and-order system by calling the incident an "accidental slip," until the police unravelled a "meticulously planned execution" of Ketan.

We take a closer look.

What is gait analysis?

The analysis examines an individual's walking pattern. Officials who probe homicide, robbery and sexual assault cases increasingly rely on gait analysis as it helps them when CCTV footage is unclear, or suspects have concealed their identity.

This forensic technique focuses on identifying unique characteristics including stride length, posture, arm movement and overall body mechanics.

Gait analysis by investigators can serve as solid corroborative evidence in a case, said LN Rao, a former Delhi Police Special Cell officer.

"It involves analysing a suspect's walking pattern, including gait, body posture and the angles of movement. Forensic experts examine these movement patterns to establish crucial facts. While gait analysis is not conclusive evidence on its own, it can significantly strengthen the overall case when supported by other evidence," he added, as quoted by NDTV.

While individuals may have comparable height or physique, their gait is usually unique, reflecting differences in anatomy, limb movement, muscle coordination, prior injuries, and habitual movement patterns.

Forensic specialists then carry out the walk comparison using this software, which examines videos frame by frame. It is important to note that gait analysis is not conclusive evidence, like fingerprints or DNA; however, it can assist or even challenge the probe alongside other evidence in the case.

Why police want to conduct Chaudhary’s gait analysis

Investigators argue that by recreating Chaudhary's walk, they can determine whether the person captured on CCTV is the accused. According to police, in the footage, Chaudhary's face is not visible as he was wearing a hoodie, leaving officials probing the matter to rely on gait analysis.

"We are planning to conduct a gait analysis of Chaudhary. We have CCTV footage showing him walking while wearing a hoodie to hide his face. The gait analysis will compare his locomotion in the CCTV footage with the recreated video to determine whether the walking patterns match," police told the court while seeking the accused's custody, PTI reported.

As part of the analysis, the accused will wear the same clothes as seen in the CCTV footage on the day of the crime. He will then walk along the same route to Lohagad Fort. Afterwards, the recreation recording will be compared with the original footage to identify similarities in movement.

“Chaudhary would be dressed in his original Hoodie attire and made to walk again at the same spot at Lohagad Fort, and the new video-recorded walk would be compared with that of CCTV footage recorded on June 18. Using AI tools, we will analyse the similarity, and it will help confirm his presence," a senior police officer said as quoted by the Indian Express.

How gait analysis can crack the Ketan case

Several experts are stressing that gait analysis can help identify the accused and crack the case quickly.

Mayank Gurjar, the Deputy Commissioner of Police North, Raipur, called the gait analysis "significant" in the Pune murder probe, adding that facial recognition may not be possible due to concealment of the identity.

"Every individual has a distinctive walking pattern shaped by skeletal structure, posture, stride and biomechanics. Even when a suspect conceals facial features, these characteristics often remain consistent," Gurjar explained, NDTV reported.

According to Gurjar, placing Chaudhary at the crime scene using gait analysis will strengthen the chain of circumstantial evidence. The DCP emphasised this analysis is "corroborative evidence and cannot, by itself, establish guilt."

Sunny Nehra, a cybersecurity expert, noted that in the Ketan Agarwal murder case, this analysis is "paramount" due to concealed identity on CCTV, making facial identification difficult.

Nehra adds that a person can hide their face or change their clothes; however, they cannot alter their natural biomechanics, making gait analysis one of the most promising methods for solving the case.

Cyber expert Raj Shekhar said: "In most cases where CCTV footage plays a crucial role, poor image quality or camera distance makes facial identification difficult. AI can analyse movement patterns and significantly improve the chances of correctly identifying a person. In the near future, AI-assisted analysis of CCTV footage will become routine, not only for police investigations but also for private security systems."

With inputs from agencies