Contrary to what some have said. In the episode "Sergeant of the Guard" the character of the CID Investigator is not a goof. Prior to 1999 and a MOU signed btwn the Navy and the Marine Corps, their was an federal agency called the United States Marine Corps Criminal Investigation Division (USMC C.I.D.). They were the only agency responsible for investigating felony level offenses besides the F.B.I. on Marine Corps Installations. During this episode and the time period being depicted; the USMC C.I.D. would have been the appropriate law enforcement agents.
At this time frame of this episode, NCIS which use to be called the Naval Investigative Service (NIS) was responsible for only Navy bases.
In 1992, after the botched "Tail Hook" investigation by the then NIS; Navy officials had to improve their brand and scrambled to restructure. For the next 7 to 8 years NCIS leadership pressured the Marine Corps to take over responsibility for felony investigations and eventually absorbed the approximate 300 military Special Agents and resources from USMC C.I.D. into the now NCIS.
So yes, this episode referring to the USMC C.I.D. Agent is accurate. Also at this time USMC C.I.D. Agents were trained by the U.S. Army CID at USAMPS. Hence the similarity in name of Criminal Investigation Division.
Now you know!
