December 13, 2001: Pak-based terrorists carry out an audacious attack on the Indian Parliament killing eight security personnel and a gardener; all five terrorists are killed in their gun-battle with policemen deployed at the citadel of Indian democracy; the case is solved and all accused arrested within 72 hours.

December 16, 2012: a 23-year-old physiotherapist is brutally gang raped in a moving bus in Delhi; the case is cracked within five days despite the lack of initial leads; a head constable loses his life in the line of duty during riots that follow the dastardly crime.

In Khaki Files, Neeraj Kumar, a former Delhi Police Commissioner revisits many such high profile police cases of his career -from investigation of one of the biggest lottery frauds in the country to foiled ISI attempt to kill Tarun Tejpal and Anirudh Behal of Tehalka-bringing to light numerous achievements of the country's police force, otherwise largely reviled and ridiculed.

Neeraj Kumar is the former commissioner of police, Delhi, and the author of Dial D for Don: Inside Stories of CBI Missions.