noun
special investigation headquarters
Refers to a temporary task force or headquarters set up by police or prosecutors for a specific high-profile case.
警察は殺人事件のため特別捜査本部を設置した。
The police set up a special investigation headquarters for the murder case.
捜査本部 is a general investigation headquarters, while 特別捜査本部 is specifically a special or extraordinary one, often for major cases.
Compound of 特別 (special) + 捜査 (investigation) + 本部 (headquarters).