Legal term for a person held in custody, typically in a police station or detention facility.
The rights of detainees are protected by law.
Refers to the act of detention itself, while 被留置者 specifically means the person being detained.
A suspect under investigation, not necessarily in custody. 被留置者 is a detainee, who may or may not be a suspect.
Compound of 被 (hi, 'receiving') + 留置 (ryūchi, 'detention') + 者 (sha, 'person'). The exact historical derivation is uncertain, but the word follows standard legal terminology patterns.