Kolkata, Sep 12 (IANS): The Central Bureau of Investigation (CBI) officials have collected the teeth impression of civic volunteer Sanjay Roy, who has been arrested for the rape and murder of a junior doctor of RG Kar Medical College & Hospital in Kolkata in August.

Sources said that a team of CBI officials reached the Presidency Central Correctional Home in South Kolkata late on Wednesday evening.

Besides interrogating Roy on the basis of fresh findings in the rape and murder case, the central agency officials also collected his teeth impression, sources added.

According to them, teeth impression of the accused is often considered as important evidence in any investigation in rape or murder cases.

Roy was first arrested by the cops of the special investigation team of Kolkata Police, who were carrying out the initial investigation in the matter before a Division Bench of the Calcutta High Court handed over the charge of the probe to the CBI.

Right now the main focus of the CBI’s investigation is to be sure whether Roy was the only perpetrator of the crime or whether there was the involvement of others in the rape and murder of the doctor.

The Investigating Officers are also looking at suspected tampering of evidence as well as severe lapses on the part of the city police which conducted the initial probe before it was handed over to the central agency.

Sources added that many lapses have been flagged in the initial investigation, including the amateurish language used in the post-mortem report, lackadaisical videography of the autopsy, contradictions over the garments worn by the victim in the post-mortem report, and the seizure list of the Kolkata Police.

The central agency is now trying to ascertain whether the lapses were out of sheer callousness, or were a deliberate act to mislead the probe.

Last week, Governor CV Ananda Bose had also highlighted the 'flaws' on the part of Kolkata Police in handling the probe. On September 6, a special court in Kolkata extended Roy's judicial custody by 14 days.