The Criminal Investigations Division is a division within the Operations Bureau of the Gretna Police Department. This division is manned by 10 officers, 1 lieutenant, 1 sergeant and 8 investigators. This division is comprised of two units: General Assignment and Narcotics Iinvestigations.

The General Assignment Unit is responsible for investigating all major criminal offenses inclusive of homicide, armed robbery, sexual assault, child abuse, burglary and other violation of the law. The Narcotic Investigations Unit is a proactive operation charged with the responsibility of investigating crimes involving all narcotic violation, vice and public moral crimes. This unit is also responsible for all asset seizures. This unit is a member of the Multi Jurisdictional Task Force and various other federal, state, and local task forces.

The Criminal Investigation Division is available 24 hours a day to respond to the investigative needs of the department and the citizens of Gretna.