Aftab Amin Poonawalla, the accused in the Shraddha Walkar murder case, was again brought to the Forensic Science Laboratory (FSL) office in Delhi on Tuesday for polygraph test.
This is his fifth session at FSL, and Aftab is being provided a tight security after Monday's incident that saw the vehicle carrying him being targetted by sword-wielding men. Authorities have deployed Border Security Force (BSF) personnel outside the FSL office, reported ANI.
Meanwhile, decks have been cleared for Aftab's narco test which is scheduled for December 1.
The polygraph test is lagging as Aftab reportedly had been "misleading" the investigating officers. "The expert team is conducting polygraph tests. Today’s session will be completed soon. We may need to continue the test on Tuesday as well. Once our tests are completed, the narco test will be conducted," FSL director Sanjeev Gupta told ANI.
On Monday evening, a police van carrying Aftab was attacked by some weapon-wielding people outside the FSL. According to reports, two men, who came in a car, stopped the vehicle carrying Aftab before attacking it.
The van was driven out of the spot while two attackers were detained, the police said. Videos showing a police officer pulling out his service revolver to disperse the attackers carrying swords had gone viral on social media.
The attackers reportedly belonged to a right-wing group and said they intended to chop Aftab into pieces to avenge the killing of Shraddha Walkar.
Delay in DNA analysis
Experts have raised questions over the delay in DNA profiling amid reports of no conclusive proof that the body parts recovered in the Mehrauli murder case belonged to Shraddha Walkar.
Police have reportedly recovered 12 human body parts on November 13, and these have been sent to a laboratory for analysis.
However, authorities haven't revealed anything about the same. "We cannot reveal anything about the body parts found since we have to maintain high secrecy in such cases," Assistant PRO at Forensic Science Laboratory, Rohini, Dr Rajnish Kumar Singh said.
Top forensic experts believe the delay is inexplicable. According to them, specialists should not ideally take more than 24 hours to ascertain a person's identity from remains even if they are six months old.
Gyaneshwar Chaubey, professor of genetics at Banaras Hindu University, told PTI that 24 hours is a good time to extract the DNA from a year-old human remains even if it is unpreserved. Chaubey was part of the team that solved the 400-year-old murder mystery of Georgia's Queen Ketevan through DNA analysis in 2021.
"We may not get flesh after six months or a year but bone marrow, a tissue found inside the bones, survives for more than a year and it makes DNA extraction easy," he said.
Dr K Thangaraj, senior scientist and director, Centre for DNA Fingerprinting and Diagnostics (CDFD) under the Union government, said the entire analysis depends upon "the quality of samples, isolation of DNA from biological remains, selection of appropriate DNA markers, and most importantly, trained manpower".
Institutions like CDFD and the Centre for Cellular and Molecular Biology (CCMB) have handled DNA samplings of high-profile assassination cases, such as that of former prime minister Rajiv Gandhi and former Punjab chief minister Beant Singh.
"In the 1980s and 90s, the technology was not so advanced and it used to take about 10 days to generate a DNA profile/fingerprint, but today, generating a DNA profile of fresh samples should not take more than 24 hours," he added.
He further said in Walkar's case, isolating DNA from six-month-old samples may be challenging, but experts who have handled samples of similar nature would not take more than three days to establish the identity.
(With inputs from PTI)