The functional areas within the sheriff's office are separated into divisions to allow for effective and efficient control of its numerous processes. The following briefly summarizes each division's responsibilities.

The Administrative Services Division is responsible for recruiting, hiring, and training the most highly qualified personnel to staff both the sheriff's office and the detention facility. This process is conducted by the Professional Standards Section, which receives, screens, and investigates all applicants for employment. This section is also responsible for conducting internal affairs investigations. The law enforcement profession is constantly evolving, In order to implement new technologies, comply with changing laws, and meet the increasing needs of the county's citizens, the Training Section staff researches, develops, and conducts comprehensive training programs for employees at all levels.

The Support Services Division includes records, communications, and several support service functions. Staff in the Records Section handles all processing, maintenance, and storage of sheriff's Office records, which includes offense, arrest and jail reports, and investigative records. The Records Section also processes arrest warrants received from the court system, and prepares crime reports for the state and F.B.I. Emergency 9-1-1 phone service, computer-aided-dispatch, and all radio communications are provided in the public safety communications center by staff assigned to the Communications Section. Staff within the Support Services Division is responsible for providing four primary services: Fugitive, which locates, arrests, and transports wanted persons; Civil, which processes and serves documents related to civil court proceedings; Mental Health, which serves court documents, processes emergency commitments, and provides crisis intervention in cooperation with the county's mental commitments court and the Collin County Mental Health Mental Retardation Center. The last support function is vehicle fleet and equipment maintenance coordination.

The sections within the Field Operations Division are the most highly visible operations in the sheriff's office. Foremost is the Patrol Section which is responsible for responding to calls for service from citizens, conducting preliminary investigations of criminal violations, and detecting and arresting those who violate the law. The patrol staff assists stranded motorists, provides traffic control, and aids other law enforcement agencies in times of crisis. Staff assigned to the Criminal Investigation Section investigates reported criminal offenses by gathering evidence, collecting statements and preparing all paperwork necessary to file cases with the district attorney's office. The Narcotic Section investigates violations of controlled substance laws, particularly those involving illegal activities of career criminals.

Several of the field operations approach the issue of crime in a proactive manner by offering services and educational programs to help citizens reduce their vulnerability to crime. The Crime Prevention Section staff, for example, conducts home and business security surveys, provides safety programs for children and adults, and maintains the Neighborhood Crime Watch Program. In addition to investigating violations of State Health and Safety Code, which include illegal dump sites, the Health and Safety Section staff also provides special programs for students, and training for citizens and officers from other law enforcement agencies.

Also within the Field Operations Division are the Tactical Operations Team and the Reserve Unit. The Tactical Operations Team is a group of specially trained officers who respond to high risk situations, including barricaded suspects, narcotics raids, hostage situations, and searches for suspects, evidence, and lost individuals. The Reserve Unit is wholly comprised of unpaid volunteers who have received the same training as full time sheriff's deputies, and are utilized to supplement all operational areas within the sheriff's office and detention facility.