The Criminal Investigations Division of the Sheriff's Office consists of two main units responsible for investigating specific types of crimes.

The two units are CID Investigators and Narcotics Investigators. Each unit has a Sergeant responsible for case coordination and daily oversight.

CID Investigators are responsible for bringing positive resolution to crimes against persons and property. This highly trained group of investigators solves crimes involving; sexual assaults, homicides, thefts, burglaries, robberies, and follow-up incidents from the patrol division.

There are eight CID Investigators who are not only assigned to general cases but also hold specialty training in; Crime Scene Investigations, Computer Forensics, Internet Crimes against Children, and Polygraph. A CID Investigator is also assigned and dedicated solely to the Sex Offender Task Force.

Narcotics Investigators are responsible for planning and conducting covert and overt drug related enforcement operations. The Narcotics Unit consists of six Investigators with one being assigned to the DEA resident office in Fayetteville, AR. The Narcotics Investigators are highly trained in detecting illicit drug trafficking organizations through the use of undercover infiltration and techniques.

Both CID Units receive intense continuous training in their area of expertise. Investigators use cutting edge technology to stay proactive in the fight against crime. High-tech computer forensics, evidence collection tools, and surveillance equipment are just some of the tools utilized daily to give CID a competitive edge against rapidly evolving criminal elements in Benton County and Northwest Arkansas. CID has recently added a large, state-of-the-art, evidence building equipped with an enclosed processing area for items such as ATVs, vehicles, and boats.