Final answer:
The U.S. Army Criminal Investigation Command (CID) is a military investigative service that investigates crimes related to the U.S. Army.
Step-by-step explanation:
The military investigative service I studied is the U.S. Army Criminal Investigation Command (CID). Its purpose is to investigate and solve crimes that involve the U.S. Army, including crimes committed by or against Army personnel.
The CID is composed of special agents, known as CID agents, who are trained in both law enforcement and military procedures.
The CID investigates a wide range of crimes, including but not limited to murder, sexual assault, fraud, theft, and illegal drug activities. They gather evidence, interview witnesses, and conduct thorough investigations to bring the perpetrators to justice.