chennai pakkiriswamy chandra sekharan a doyen of forensic science who pieced evidence that helped unravel the assassination of rajiv gandhi died at private hospital here at 230 pm on tuesday he was 83 chandra sekharan hospitalised a died related health problems said the padma awardee was proponent and a pioneer in the country of skull superimposition technique a method he effectively to identify one prime accused in the of the former prime minister the human bomb thenmozhi also known as was a first of kind innovation forensic sciences mastered the skill of matching photographs of skulls those of the deceased till then matching of was the only means of identifying a body said k ragothaman cbi chief investigating officer in the case recalling the close association he had with and how lip reading for criminal investigation was a hobby of the forensics expert brought out a voluminous report which the special court found to valuable evidence the case he went on write a book the human bomb insights into investigation the case it chandra sekharan who first said rajiv assassin was a bomb he was a professional even after retirement as many investigating agencies including the premier nia sought his assistance as a consultant his word was often the last word on investigation for police officers he seldom disappointed the man did not play by the rules all times chandra sekharan stumbled upon piece evidence an exposed film from the assassination which identified the killers handing it over to police he gave it to a newspaper photographer first but finally he was the one who preserved it and it proved to be valuable evidence said ragothaman prof k who worked as a junior to chandra sekharan for 23 years said the former director of tamil nadu forensic sciences department was on crime scenes