page_title: Prefectural police department
section_title: Criminal investigation
hierarchical_section_title: Prefectural police department / Organisation / Prefectural Police Headquarters / Criminal investigation
caption_attribution_description: 日本語: 愛知県警察年頭視閲式にて、機動捜査隊。
context_page_description: In the law enforcement system in Japan, Prefectural Polices are responsible for the regular police affairs as to the areas of the respective prefectures. Although these Prefectural Polices are in principle regarded as municipal police, they are, in fact, in many parts under the central oversight and control of the National Police Agency. As of 2017, the total strength of the prefectural police is approximately 288,000: 260,400 sworn officers and 28,400 civilian staff.
context_section_description: In the Empire of Japan, the criminal investigation was presided over by prosecutors, like the ministère public does in French law. Then, with the 1947 Police Law (ja) and the 1948 Code of Criminal Procedure (ja), the responsibility of investigation has been defined to be uniquely assigned to police officers. In order to fulfil this responsibility, criminal investigation departments or criminal investigation bureaus (judiciary police) were set up in each police organisation. After the establishment of the 1954 amended Police Law, these departments are supervised by the Criminal Affairs Bureau of the National Police Agency.
  Criminal investigation departments or criminal investigation bureaus maintain two investigation divisions (捜査課, sousa-ka) (third or even fourth divisions are established in some urban prefecture), an organised crime investigation division (組織犯罪対策課, soshikihanzai-taisaku-ka) (reinforced as an independent department or headquarters in the TMPD and some prefectures), a mobile investigation unit, and an identification division (鑑識課, kanshiki-ka). The mobile investigation units (機動捜査隊, kidō sousa-tai) are first responders for initial criminal investigations, distributed among the region with unmarked cars. The special investigation teams (特殊事件捜査係, tokushu-jiken sousa-kakari) are specialised detective units of the first investigation divisions, well acquainted with new technology and special tactics including SWAT capabilities. They are mandated for critical incidents except for terrorism, but in some rural but well-versed prefectural police like Aomori, these detectives can form a counter-terrorism task force together with uniformed officers and riot specialists.
caption: Detectives of the Aichi MIU.
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