Murder of student in Ghaziabad: Main accused killed following encounter with police
The story so far: A Pune court has extended the custody of Siya Goyal and Chetan Chaudhary, the two accused in the Ketan Agarwal murder case, until July 3, 2026. The court acquiesced to the investigators, who said several aspects of the probe are ongoing, including a forensic study of Mr. Chaudhary’s gait. According to media reports, the police plan to compare the way he walks with CCTV footage showing a hooded individual near the crime scene at Lohagad Fort, arguing that the analysis could help determine whether the person in the footage was Mr. Chaudhary.What is gait analysis?Gait analysis is the scientific study of how a human walks or runs. Walking (or running) is a complex activity where the body has to coordinate continuously between muscles, bones, and the nervous system. Gait analysis breaks down these activities to piece together how a particular person walks.In clinical settings, this analysis can be used to understand why someone is in pain or how a specific medical condition is progressing. Sportspersons use it to understand how they can run faster.Likewise, forensic gait analysis has been used to assess whether the way a person walks — as recorded live or seen on CCTV footage — is consistent with that of a known individual. It is generally used as the sole piece of evidence and is usually considered to corroborate other findings, such as DNA data and/or eyewitness accounts.In most instances, experts use the analysis to identify abnormalities in an individual’s pattern of movement. For example, sometimes a person’s back pain may be related to the way their foot strikes the ground. Doctors also use gait analysis to manage symptoms in people with cerebral palsy and Parkinson’s disease and as part of post-stroke care.In fact, in Parkinson’s disease, Alzheimer’s disease, dementia with Lewy bodies, and multiple sclerosis at least, research has found that changes in gait can appear years before their more obvious symptoms.What is a gait cycle?To understand the way a person moves, experts begin with looking at the gait cycle — the series of events starting from the moment one foot touches the ground until the same foot returns to the ground again.The cycle has two broad phases. In the stance phase, your foot is in contact with the ground and ends when the toes push off. The body absorbs the shock of hitting the surface while supporting your whole body weight in this phase. In the swing phase, the foot is off the ground but also moving towards it, to take the next step. In this duration, the body’s focus is on ensuring the toes don’t drag on the floor while positioning the foot for its landing.During gait analysis, an individual makes multiple gait cycles while experts use instruments to track the steps per minute, step length, stride length, the angles of the legs’ joints, ankle rolls, and the force with which the foot strikes the ground. Sometimes, the instruments are just a clinician’s eyeballs and a notepad, so as you walk back and forth, they record different aspects of your movement.These days, experts also record a person’s gait cycles on video and analyse it with a computer later, use sensors called pressure mats and force plates to track where your feet apply the most pressure, and wearable sensors attached to the person’s body to track their movement in a real-world setting, like at a crime scene or on a sports field.How is forensic gait analysis different?In forensic gait analysis, experts may be able to use a person’s walk to identify them in a video the same way a person’s fingerprint can be used to identify if they have touched a surface.In the case of Ketan Agarwal’s death, the police have said they have a video of an individual near the scene of the crime and that it could be one of the suspects, Chetan Chaudhary. The person’s face in the video is obscured by a hoodie, however, so the police hope to confirm if that is indeed Mr. Chaudhary using gait analysis, among other methods.In such cases, typically, ex
