Florida officers typically use three standardized field sobriety exercises: the HGN eye test, the walk and turn, and the one leg stand. Each is meant to follow national NHTSA standards, and results can fail when those standards are not met.
The three standardized roadside exercises
In the horizontal gaze nystagmus test, or HGN, the officer moves a stimulus, such as a pen or small light, from side to side while watching the person's eyes for involuntary jerking. The walk and turn asks the person to take heel to toe steps along a line, turn, and walk back. The one leg stand asks the person to hold one foot off the ground for a set time while counting.
These three are the exercises NHTSA standardized. Officers sometimes use other tasks, such as reciting the alphabet or counting backward, but those are not part of the standardized set.
Why the standards decide how much a result is worth
Each standardized exercise comes with instructions for how it is explained, demonstrated and scored, and the clues an officer is supposed to look for are defined in advance. When an officer skips instructions, gives a confusing demonstration or scores loosely, the result no longer reflects the exercise as designed.
That is why the officer's training, and how the exercises were actually given as shown on video, often say more than the summary in a police report.
Conditions that can produce a poor performance
Roadside exercises are often given at night beside traffic, with flashing lights and an uneven or sloped surface. Footwear, weather, wind and fatigue can all affect balance.
Personal factors matter too. Age, weight, injuries, inner ear problems and some medical conditions can make the walk and turn or the one leg stand difficult even for a sober person. Nervousness during a police encounter is normal and can affect coordination.
How the defense reviews field exercise evidence
The review starts by comparing the officer's description with the video. Did the instructions match the standards? Were the conditions reasonable? Did the officer report clues that the recording does not show?
It also considers what role the exercises played. Field exercise results are offered as evidence of impairment of normal faculties, one of the two ways the state can establish DUI, and they tend to carry more weight when there is no breath result. DUI Lawyers Shield Firm reviews field sobriety evidence and video in a free case review.
Keep reading
- Boating Under the Influence in Florida: What BUI Arrests Look Like
- Challenging the Horizontal Gaze Nystagmus (HGN) Test in Florida DUI Cases
- What Happens at a Florida DUI Arraignment
General information only, not legal advice. Every case depends on its own facts, and prior results do not guarantee a similar outcome.
Talk to a former prosecutor now.
Confidential case review, available 24 hours a day.