Criminal Investigation Department, West Bengal, was founded in 1906, primarily to cover the terrorist / extremist elements which arose in the Indian Freedom Movement following the Partition of Bengal. Prevention and detection of crime became its sole brief after Independence.

Through much of its history, CID was headed by the Dy. Inspector General of Police, CID. In recent years, CID has been headed by the Addl. Director General of Police, CID, assisted by Inspector General of Police-I, CID, Inspector General of Police-II, CID as well as by DIG, CID, DIG CID(Operations) and DIG CID (Special Cell). IGP-II supervises the work of DIG, CID, while IGP-I supervises the work of the other two DIGs. DIG CID supervises the sections concerned with Homicide, Dacoity / Robbery, Cheating / Fraud, Economic Offences and Motor Theft, and also looks after all establishment matters. Support units such as Photography Section, Finger Print Bureau and Questioned Documents Examination Bureau are also under DIG CID. DIG (Operations) looks after Maoist matters, Terrorist matters, kidnapping / extortion, FICN, Cyber Crime and Railway / Highway Crime. DIG (Special Cell) looks after Anti-Human Trafficking Unit / Protection of Women and Children Cell, Narcotics Cell and Missing Persons Bureau. CID has one or more field units in each of the districts, headed by 1-2 Inspectors, called District Detective Units (DD Units). DIG CID supervises the DD units of South 24-Parganas, North 24-Parganas, Howrah, Hooghly and Purba Medinipore. DIG (Special Cell) supervises all districts from Nadia to Coochbehar. The remaining districts, in the western part of the State, are supervised by DIG (Operations).

The cases taken up by CID are its typically those that are too difficult for district police, or involve Inter-District / Inter-State ramifications or are particularly sensitive for some reason. CID takes over cases by order of ADG, CID, or by the order of DG&IGP, West Bengal or on the instructions of Government, or by the orders of a competent Court. Relatively straightforward cases are given to the District Detective Units, while the complex cases will go to the headquarters unit specializing in that form of crime. Each headquarters unit and each DD unit are headed by 1-2 Inspectors. Two or more units are supervised by a Dy.SP. Each Special Superintendent of Police (SS, CID) supervises the work of a few Dy.SsP. In addition, SS-I also looks after establishments matters.

CID has some specialized support units. The Finger Print Bureau of CID, WB is the oldest in the world, and is modern and computerised. The Questioned Documents Examination Bureau is the oldest of its kind in India. The Special Control Room of CID looks after data analysis, and is state-of-the-art. The Bomb Detection and Disposal Squad (BDDS) is also state-of-the-art, with a large unit in Kolkata and a smaller unit in Siliguri.

CID has kept abreast of recent trends in crime. The growing prevalence of Cyber Crime is well looked after by the Cyber Crime Cell. The sections dealing with Terrorism and Maoism are among the best in CID. The Narcotics Cell of CID has had a record haul last year. Regarding trafficking for commercial sexual exploitation, an Anti-Human Trafficking Unit was inaugurated by the Hon’ble Chief Minister in 2007, and has funding from the United Nations.

Dacoity / robbery, Homicide and white collar crime continue to be important.

Regarding its assigned role as the premier crime fighting agency of the State, CID has five distinct advantages. First, its systems approach in the monitoring of investigation ensures that every single case is subjected to successively higher levels of scrutiny. Secondly, despite the attrition of annual transfers, CID still has many skilled and dedicated investigators at every possible rank. Thirdly, the relatively small number of cases it takes up means that most cases, and certainly all important cases, get the individual attention of Senior Officers. Fourthly, it has a presence in every district, however skeletal, meaning that criminal intelligence is available from every corner of the State. And finally, as the apex body, it is relatively insulated from the pulls and pressures that District Police is occasionally subjected to.

Because of its strengths, CID has had some spectacular successes throughout its existence. The following are some that took place in recent years.

Soumen, the State Secretary of the CPI(Maoist) was arrested by the CID in February, 2008. In the sensational Roma Jhawar abduction case, the case was detected by CID in a very short time, and CID has even obtained conviction very recently. The entire ransom money of Rs.20 lakhs was recovered by the CID. The Khadim abduction case was detected by CID, and its trial is being actively pursued. In the Shriram Buchasia abduction case, the case was detected by the CID and Rs.23.00 lakhs of ransom money recovered. Several extremists of HUJI, LeT, Jaish-e-Mohammed have been arrested by Special Operations Group, CID with assistance from sister agencies.

Recovery of stolen vehicles, arms recoveries and seizures of FICN are frequent. In the recent incident of tiger poaching in the Sundarbans, the poacher was identified and arrested from a remote island within weeks.