Types and circumstances of crime vary significantly, and inherently require an equally diverse set of skills, resources and experience to effectively investigate and apprehend suspects. The Detectives Unit investigate cases not closed by initially responding patrol deputies that include homicide, sexual assault, burglary, fraud, and crimes against vulnerable populations such as children and the elderly. In addition, MCSO has a detective assigned to INTERCEPT (Inter-agency Child Exploitation Prevention Team), an agency which combines the resources of local, state and federal law enforcement agencies joined in the fight against on-line child sexual predators.

There's no statute of limitations on murder, and MCSO has committed resources to keeping the investigations of unsolved cases alive with the Cold Case Team, using a select group of staff and retired MCSO detectives who tirelessly volunteer their experience and service. The case of Carol Keightley, an 18-year old found dead in a ravine off the highway 11 days after her mother reported her missing, is just one of MCSO's 35 unsolved homicides whose evidence and tips are repeatedly combed over in an effort to bring closure to the victims and families, and justice to the perpetrators.

A growing problem in Multnomah County is the human trafficking industry. Affecting both foreign and domestic populations, crimes of forced labor and sexual exploitation are mostly hidden from public awareness yet devastating to victims, their families and the community. Several factors are contributing to the problem, such as the County being positioned along the I-5 corridor, the diversity of our community where 14% of residents are foreign-born and nearby farming areas that depend on hired labor ten months out of the year. MCSO investigates human trafficking crimes, provides outreach and assistance to victims, and develops and presents training for law enforcement agencies and resource groups to identify and aid human trafficking victims.