CID - Criminal Investigation Department
Crime Investigation Department, headquartered in Pune, is a specialized wing of Indian Police force, that helps in maintaining law and order in the country. The department has their own ranks of officers like Inspectors, Sub-Inspectors, Superintendents, Additional Director General of Police or Special Commissioner of Police. They usually work in plain clothes or something called Mufti.
What does CID do
Their tasks is to investigate criminal cases, like theft, murder, rape, robbery and other types of crimes assigned to them by the government of India. The investigation can span multiple districts, cities or even states depending upon the crime. Sometimes, the local police of that region also gets involved in solving the case assigned to CID. The officers usually add the word 'detective' before their rank.