What Do Officers Look for During a DUI Stop?
When an officer pulls a driver over on suspicion of impaired driving, they begin gathering evidence the moment they notice the vehicle. The things officers look for during a driving under the influence (DUI) stop include driving patterns, physical signs of intoxication, behavioral cues, and the results of roadside testing. If you’re facing DUI charges, a Greenville DUI defense lawyer can help you make sense of what happened and what comes next.
Initial Driving Behaviors
Before an officer ever activates their lights, they watch for driving patterns that suggest possible impairment. The National Highway Traffic Safety Administration (NHTSA) has identified several visual cues that officers are trained to recognize on Greenville roads:
- Weaving within or across lanes
- Drifting or straddling lane lines
- Driving significantly under the speed limit
- Stopping abruptly or without cause
- Wide turns or improper signaling
- Following other vehicles too closely
- Slow response to traffic signals
Physical Indicators
Once a driver has been stopped, the officer approaches the window and immediately begins looking for physical signs of intoxication. These observations often appear in the arrest report and form the basis for further investigation:
- Bloodshot or watery eyes
- Flushed face
- Slurred or thick speech
- Odor of alcohol on breath or clothing
- Disheveled appearance
- Trouble locating license or registration
Behavioral Clues
Officers also pay close attention to how a driver acts and responds during the encounter. Small details can shape the officer’s overall impression and their decision to escalate the stop:
- Fumbling with documents
- Confusion about location or destination
- Unsteady movements when exiting the vehicle
- Inappropriate emotional responses
- Difficulty answering simple questions
- Admissions about drinking earlier in the evening
Field Sobriety Tests (FSTs) and Evaluation
If the officer suspects impairment, they will typically ask the driver to perform standardized field sobriety tests (FSTs) on the side of the road. The three tests endorsed by NHTSA each measure different aspects of physical and cognitive function:
- Horizontal Gaze Nystagmus: The officer watches the eyes for involuntary jerking as they follow a moving object.
- Walk-and-Turn: The driver takes nine heel-to-toe steps along a line, turns, and returns the same way.
- One-Leg Stand: The driver lifts one foot about six inches off the ground and counts aloud until told to stop.
Breathalyzer and Chemical Tests
After roadside testing, officers often request a breath sample to measure blood alcohol content (BAC). Under S.C. Code § 56-5-2950, South Carolina’s implied consent law, refusing a breathalyzer or blood test results in an automatic license suspension, even if the driver is never convicted of DUI. A BAC of 0.08% or higher creates a presumption of impairment for drivers over twenty-one.
Challenging Officer Observations in a DUI Case
The observations recorded in a police report are not the final word, and many of them can be questioned through careful review of dash-cam footage, body-cam recordings, and testing protocols. Call Ryan Beasley Law at 864-756-4204 or reach us through our online form to schedule a confidential consultation with a Greenville DUI defense attorney who will examine every detail of the stop and bring experienced trial preparation to your defense.