You missed the episode - they showed a new guy who took a survey at the home of the culprit and found out that his grandmother was burnt alive by the local sarpanch, who went on to become an MLA in Maharashtra (even though the original village seemed to be in Rajasthan, judging from the dialect). That guy later surfaced at headquarters and the ACP introduced him as a new member transferred from Hyderabad to Mumbai. Essentially, he mined all the facts about the criminal as well as the MLA.
Varun - Rohit Purohit's character - is not an official member of the police force: he's just doing work for the police as a part of rehabilitation into an honest living. 😆