The Farmers Branch Police Department is a full-service law enforcement agency that operates various divisions, including criminal, special and technical investigation units. It operates a crime lab that includes forensic experts, medical examiners, crime lab technicians and photographic service personnel. The Farmers Branch Police Department offers a range of forensic services and programs, such as drug, firearms and ammunition, DNA and breath-alcohol analysis and identification programs. It also offers photographic and digital imaging and expert witness testimony services. The Farmers Branch Police Department operates a group of volunteer amateur radio operators who provide auxiliary communication services during emergencies, earthquakes, civil disturbances and other disasters. It operates an explosive ordnance disposal squad that identifies and disposes off improvised hazardous devices, explosive contraband, small arms ammunition and law enforcement chemicals. The Farmers Branch Police Department is located in Dallas.

The Rowlett Police Department, established in 1971, is a full-service law enforcement agency that employs a staff of more than 100 sworn offices, civilians and community volunteers. It supports Drug Abuse Resistance Education (D.A.R.E.), which is an international education program that seeks to prevent the usage of illegal drugs, gang activities and violent behavior. The Rowlett Police Department maintains a Special Weapons and Tactics (SWAT) team, which specializes in bomb disposal and hostage and barricaded gunman situations. The department has an honor guard that marches in parades, conducts funerals for officers and their family members, and attends wakes and funerals for area officers killed in the line of duty. Located in Rowlett, Texas, the Rowlett Police Department also maintains accident investigation, bike patrol, field training, K-9 and crisis negotiation units.