1. A suspect in the Kolkata doctor murder case, Sanjay Roy, has been revealed to be a habitual offender with a history of violence against women.

2. Roy has been arrested after the police investigation revealed his involvement in the sexual assault and murder of a female doctor at RG Kar Medical College and Hospital in Kolkata.

3. Roy, a civic volunteer, has been accused of violence in his four failed marriages, with his fourth wife filing a domestic violence complaint against him.

4. Roy was caught due to a Bluetooth earphone found at the crime scene, which he had hidden in his throat during the incident.

5. Media reports suggest that Roy was involved in a job scam racket and would promise people police jobs in exchange for money.

6. The lack of CCTV coverage in the hospital where the crime took place has raised concerns about security measures and the role of hospital authorities in such cases.