noun
detention center; jail; prison
Specifically a facility where suspects are held before trial or during investigation, distinct from a prison for convicted criminals (刑務所).
容疑者は拘置所に移送された。
The suspect was transferred to the detention center.
彼は拘置所で裁判を待っている。
He is awaiting trial in the detention center.
留置所 is a police detention facility for short-term holding, whereas 拘置所 is a larger detention center under the Ministry of Justice.
Compound of 拘置 (こうち, 'detention') and 所 (しょ, 'place'). The term is a modern legal term for a detention facility.