Finding The Flaws In A Field Sobriety Test

• Feb 27 2019

A poor performance on a roadside sobriety exercise does not end a DUI defense. The State must prove the charge, and the exercise must be evaluated in context. It is equally inaccurate to describe all standardized sobriety testing as scientifically baseless.

Standardized Exercises Have Limits

NHTSA training materials describe a standardized battery of horizontal gaze nystagmus, walk-and-turn, and one-leg-stand tests and the research supporting their use under specified conditions. They are not infallible, do not directly measure blood-alcohol concentration, and should not be treated as automatic proof of guilt. Nonstandard exercises do not necessarily share the same validation.

Reliability depends on the exercise, instructions, administration, scoring, and individual circumstances. An attorney can compare the officer’s report with video, training, and the applicable protocol.

Issues Worth Examining

• Whether instructions and demonstrations followed the required protocol.
• Whether the surface, lighting, weather, footwear, or nearby traffic affected performance.
• Whether injury, balance problems, age, medication, hearing, language, or another condition provides an alternative explanation.
• Whether the reported clues match the video and were scored correctly.

Flashing lights and moving visual stimuli may matter to particular observations, but they do not automatically invalidate every exercise. A medical condition or administration error may affect weight, admissibility, or probable cause; suppression is not guaranteed. Permitted testimony and terminology depend on the test, foundation, governing law, and the judge’s rulings.

Physical Exercises Versus Chemical Tests

Roadside exercises are different from breath, urine, or blood testing under Florida’s implied-consent law. Refusing a physical exercise does not itself trigger the chemical-test-refusal suspension, but may have evidentiary consequences. Chemical-test refusal has separate statutory prerequisites and consequences. Do not assume the same advice applies to every kind of test.

Reviewing Your DUI Evidence

Valiente Law can examine the stop, the exercises, any recordings, and chemical-test evidence to identify supported challenges. Contact us to discuss your case.

Posted in: DUI