case file; dossier; all documents related to a case
Refers to the complete set of papers and documents concerning a particular matter, often used in legal, administrative, or investigative contexts.
The lawyer submitted the case file to the court.
This dossier contains all the records of the case.
Compound of 一件 (one case/matter) and 書類 (documents). The exact historical derivation is uncertain, but the meaning is transparent from its components.