Criminal Investigation Files (刑侦档案) by Qingyun Xiaoshi is a highly regarded Chinese Danmei (BL) novel featuring intricate, episodic police procedurals focused on criminal psychology. The story follows Captain Song Wen and Lu Siyu as they solve cases, with fans noting the series' strong, stable relationship development. For more details, visit The StoryGraph
Many famous novels utilize the "file" or "dossier" style where the reader sees the evidence alongside the protagonist: In Cold Blood criminal investigation files novel