What is the detection Phase 1 in DUI investigations?

Detection Phase 1 in DUI investigations refers specifically to the observation of a vehicle in motion. This phase encompasses the initial observations made by law enforcement regarding the driving behavior of a suspect, such as erratic movements, speeding, swerving, or failing to adhere to traffic signals. These indicators serve as critical initial cues that suggest a driver may be impaired due to alcohol or drugs.

The observations made during this phase are foundational for proceeding to the next stages of DUI enforcement, including stopping the vehicle and conducting further investigations. The other phases, such as personal contact and field sobriety testing, occur later in the process after the vehicle has been stopped and the officer has made initial contact with the driver. Therefore, detection Phase 1 specifically focuses on the actions and conduct of the vehicle while it is in motion, which is essential for establishing probable cause for a traffic stop.