The Department of the Army Criminal Investigation Division (CID), previously known as the United States Army Criminal Investigation Command (USACIDC) is the primary federal law enforcement agency of the United States Department of the Army. Its primary function is to investigate felony crimes and serious violations of military law & the United States Code within the US Army. The division is an independent federal law enforcement agency with investigative autonomy; CID special agents, both military and civilian, report through the CID chain of command to the CID Director, who reports directly to the Under Secretary of the Army and the Secretary of the Army. Unlike their counterparts at OSI and NCIS, Army CID does not have primary counterintelligence responsibilities.

Warrant officer (WO) is a rank or category of ranks in the armed forces of many countries. Depending on the country, service, or historical context, warrant officers are sometimes classified as the most junior of the commissioned officer ranks, the most senior of the non-commissioned officer (NCO) ranks, or in a separate category of their own. Warrant officer ranks are especially prominent in the militaries of Commonwealth nations and the United States.