The Government Railway Police (GRP) has approached the metropolitan magistrate court in Borivli to obtain permission to carry out narcoanalysis, brain mapping and polygraph tests on Chetan Singh, the RPF constable who gunned down three innocent passengers as well as his senior officer on the Jaipur-Mumbai Superfast Express train last month.

The GRP’s application to the court stated that as the crime was heinous in nature, they are probing the matter deeply to determine Singh’s motives. So far, they have recorded statements of more than two dozen passengers, including eyewitnesses, but their statements and the answers provided by the accused are not matching. The application stated that Singh had been lying and it seemed that he was intentionally misleading the police force.