明察暗访

Explanation: Close look from the inside out, from secretly ask understanding. Refers to the court investigation in various ways. 　　Usage: Joint type; as the predicate attribute; with approval and praise for 　　Source: Qing Lin, "Upon review the case off her visit stone works": "Chen Yang Feng imperial decrees, thorough investigation, not Cheng Cheng." Thesaurus:  Anchamingfang, Ming Zha make secret inquiries