Deposing before the court as a prosecution witness, Kumar, who was also CBI's first investigating officer of the case, said he had conducted the polygraph tests on the main accused - Rajesh and Nupur Talwar. He also told the court that Rajkumar, compounder of the dentist couple, underwent narco analysis test twice and the second test had indicated his involvement in the murders.
Kumar said a sound examination was also carried out at the Talwars' residence in front of experts from AIIMS and Central Forensic Science Laboratory. "Despite various reports submitted to CBI, nothing concrete could be found against any of the accused," he said.
Fourteen-year-old Aarushi and domestic help Hemraj were found murdered in their Noida residence in 2008. Aarushi's parents - dentists Rajesh and Nupur Talwar, are the two main suspects whose names have been mentioned in CBI's closure reports.