DU teacher devises new techniques to extract fingerprints
FORENSICS GS Sodhi has developed three chemical methods to get fingerprints even if they are doused with water, buried in soil, or burnt
NEW DELHI: GS Sodhi wanted to become a police officer as a child; a dream that was quashed when he got diagnosed with colour blindness. Now an associate professor of chemistry at Delhi University’s Sri Guru Tegh Bahadur Khalsa College, he is living his dream to nab criminals in a different way — by perfecting methods of fingerprint collection.
Sodhi, after almost ten years of research, has developed three patented chemical methods to extract fingerprints even if they prints are doused with water, buried in soil, or burnt and covered in soot.
He received the Union home minister’s research and development award for his work in forensic chemical sciences from Rajnath Singh on February 10.
According to Sodhi, criminals sprinkle water on their prints, burn the crime scene or bury the weapon to make it hard to extract their fingerprints, as conventional methods rely on the soluble components in one’s sweat to read the impressions. Sodhi has developed methods to help in such situations, by creating chemical reagents that react with the non-soluble components in sweat and fingerprints.
“The first one is a suspension of a small particle reagent in water. It reacts with the fatty acids or oils in the sweat, and is also fluorescent in nature under a good source of light which enhances the visibility of the prints,” said Sodhi.
He has also developed a phase transfer catalyst spray, which reacts with the metal ions in one’s sweat, and a nano particle-sized powder, which needs minimal water to bind with it and reveal one’s prints. While the prepara- Most common method is to dust the print with a powder. There is no chemical reaction. The powder sticks to the water content in one’s sweat and the impression (much like how talcum powder sticks to one’s body) to reveal the print.with a tape. tion of the reagents can take 10-30 minutes, the collection of the fingerprint is a two-minute job.
Sumit Kumar, a scientific assistant at the Regional Forensic Science Laboratory, said water, dirt and soot, create “disturbances” in the fingerprints, making it difficult to lift and match.
Sodhi said more research in the field, and proper training of police officials is required. Delhi Police spokesperson Dependra Pathak said all officers are trained in lifting fingerprints but many times residents rummage A reagent called ninhydrin, dissolved in an organic solvent, is used.
It reacts with the protein content of the sweat, and gives a coloured impression. These prints are then photographed and/or lifted with a tape. through belongings before police the reach, contaminating the site.
Sodhi has been pushing for a BSC honours in forensic sciences at the university and his college, but to no avail. Registrar Tarun Das confirmed that the academic council approved such a programme at SGTB Khalsa College. Jaswinder Singh, principal of the college, said that the plans have been stalled because of the question of how to finance the course, as UGC has asked them to run the course in self-financed mode, and the university had disagreed.