Special Investigation Team

Special Investigation Teams (SIT) (特殊事件捜査係, Tokushu Jiken Sousa Kakari) are tactical detective units of Japanese prefectural police forces.

As a response to these problems, the Tokyo Metropolitan Police Department (TMPD) established the SIT unit within its Criminal Investigation Bureau in 1964.

[4] All unit are established in the First Investigation Divisions (捜査一課, Sousa Ikka) of each prefectural police headquarters (PPHs).

[7] This custom evolved into the Special Investigation Dispatch Task Force (特殊班派遣部隊, Tokushuhan-haken-butai) as a formal institution of the NPA, being made up of experienced detectives selected from across the country.

The TMPD's SIT has also received advice on tactical operations from the Far East Field Office of the Naval Criminal Investigative Service in Yokosuka.

[2] However, in some rural prefectures such as Aomori, these detectives can form a counter-terrorism task force together with uniformed officers and riot specialists.

[12] On May 25, 2023, the Tokyo SIT and the Kanagawa Prefectural Police's Special Assault Team was mobilized in Nagano response to requests for assistance from the NPP in a shooting/stabbing spree.