Why Sanjay Roy’s dental impression, mouth swab could be crucial evidence in RG Kar doctor’s rape-murder

The CBI gathered dental impressions and mouth swabs from Sanjay Roy, arrested for the rape and murder of a PGT doctor at RG Kar. These were initially collected by Kolkata Police due to specific bruises on the victim. The CBI also interrogated medical staff involved in the post-mortem and certification process.