4. Investigatory records.

Under D.C. Code § 2-534 (a)(3), “[i]nvestigatory records compiled for law-enforcement purposes” may be exempt from disclosure, “only to the extent that production of such records” could interfere with enforcement proceedings, desprive a person of an impartial adjudication, invade personal privacy, disclose a confidential source, disclose investigative techniques, or endanger the life or physical safety of law enforcement personnel.