Its primary function is to investigate felony crimes and serious violations of military law and the United States Code within the US Army.

Unlike their counterparts at OSI and NCIS, Army CID does not have primary counterintelligence responsibilities, as this jurisdiction resides with United States Army Counterintelligence Command (ACI)[3] The division does not charge individuals with crimes; instead, DACID investigates allegations and turns official findings over to the appropriate command and legal authority for disposition and adjudication.

[4] USACIDC was established as a United States Army command in 1971 and is headquartered at Marine Corps Base, Quantico, Virginia.

During World War I, General John J. Pershing ordered the creation of a separate organization within the Military Police Corps to prevent and detect crime among the American Expeditionary Force in France.

As the Army had expanded, the crime rate had risen, and local commanders did not have the personnel or resources to conduct adequate investigations.

After the war, the CID was once again decentralized, with control of criminal investigations transferred to area commands in the 1950s and further down to the installation level in the 1960s.

A Department of Defense study in 1964 entitled Project Security Shield made clear that complete recentralization of the Army's criminal investigative effort was needed in order to produce a more efficient and responsive worldwide capability.

However, this arrangement did not fully resolve all the coordination problems, and in 1969, the U.S. Army Criminal Investigation Agency was established to supervise all CID operations worldwide.

[1] In 2020, the high profile murder of Vanessa Guillén at Fort Hood raised concerns related to the capabilities, experience, and resourcing of the Command.

[11] Following the fallout of the Fort Hood Report, a historical reorganization was announced in 2021, which will result in a civilian director, separation from the Military Police chain of command, credentialed military officers assigned to CID with specialized investigative training and less protective details to allow agents more time to hone their skills.

[9] The report found that the Army investigators tasked with reviewing complex crimes at Fort Hood were vastly inexperienced, overwhelmed and understaffed, resulting in failures to protect service members and their families.

Candidates must be enlisted soldiers who are US citizens, at least 21 years of age, and in the ranks of SPC-SGT or SSG with less than 12 months time in grade, and a graduate of the Basic Leader Course (BLC).

[13] To qualify for Warrant Officer positions, candidates must be at least a Sergeant/E-5, currently serving as a Special Agent, with 2 years of investigative experience with CID, have a Top Secret clearance and a bachelor's degree (waiverable).

After the 2021 reforms following the Fort Hood Independent Review Committee, CID began to increase its numbers of civilian special agents when compared to military special agents, intended to increase CID's investigative experience and help the command build better partnerships with local and regional law enforcement, as military special agents can be moved between posts after a few years of service, severing all professional contact between the different law enforcement agencies.

The Field Agent Training program will immerse the newly appointed 1811 to military criminal investigations and how to apply lessons learned at FLETC to the job.

Agents are also issued the M4A1 Carbine or shortened version, MK18, for protection missions and routine carry during enforcement related duties including when deployed overseas to war zones.

[18][19] The following is a list of former and current CID commanders:[1] Federal law enforcement JAG Corps Other Military Investigative Organizations Other