Chandigarh, Dec. 10 -- Having languished without leads for nearly two years, the probe into the November 2021 murder of Panjab University professor BB Goyal's wife saw its first real breakthrough in late 2023, when their daughter's polygraph test showed deceptive responses to crucial questions. Investigators describe this as the "turning point" that shifted suspicion firmly onto Goyal. With no physical evidence to lean on, the anomalies in her test prompted police to pursue Goyal's Brain Electrical Oscillation Signature (BEOS) profiling - an advanced neuro-forensic technique that ultimately led to his arrest on Monday. Seema Goyal, 60, was found dead in the couple's house on the PU campus in Sector 14 on November 4, 2021. Their only daughter, Parul, had been away at a friend's house since the day before. Goyal had claimed to have found Seema lying on the bed, with hands and legs tied with a cloth. However, instead of alerting the police, he called the PU senior medical officer (SMO) and moved her to GMSH-16. Police were eventually called by the hospital staff. From the outset, investigators suspected an inside job: no forced entry, no one seen on CCTV, and Goyal was the only person in the house that night. But with forensic teams unable to recover usable clues, police lacked the evidence to link him to the crime. Nearly two years later, Parul underwent a polygraph test in 2023. Two questions produced deceptive indicators: "Do you know who killed your mother?" and "Was there any dispute between your parents the night before the murder?" Officers said these responses suggested she was withholding information, reinforcing suspicion of an inside job. Police officials said after evaluating the polygraph results, a review team recommended a more advanced test capable of detecting "experiential knowledge" rather than mere recognition. This led officers to apply for permission to conduct Goyal's BEOS profiling in July 2025. BEOS, unlike a polygraph, does not rely on physiological stress responses. Instead, it records EEG brainwave patterns while the subject listens to detailed crime-reconstruction narratives, revealing whether they experienced the act. The BEOS results, officials said, indicated Goyal's direct involvement, enabling his arrest. The BEOS profiling of Goyal also indicated traces of experiential memory, suggesting a dispute between the couple prior to the murder, police sources said. Goyal remains under a three-day police remand for questioning and reconstruction of sequence of events....