The State’s case rested almost entirely on an involuntary eye movement. The jury did not accept it as proof of impairment beyond a reasonable doubt, and returned a verdict of not guilty.
This was our first trial of 2026, in county court in Pinellas County. We want to write about it because the case turned on something a lot of drivers have never heard of and would not think to question: the eye test at the roadside.
What the eye test actually measures
Horizontal gaze nystagmus, usually shortened to HGN, is the involuntary jerking of the eye as it tracks toward the side. An officer holds a stimulus, moves it across your field of vision, and looks for that jerking.
Here is the part that matters. Nystagmus is a reflex, not a behavior. You cannot perform it well or perform it badly, and you cannot practice for it. More importantly, it has many causes that have nothing at all to do with alcohol or drugs, including fatigue, anxiety, inner ear conditions, prescribed medication, neurological conditions, and congenital disorders a person is simply born with.
Our client had a congenital eye condition. It had been part of his life since birth, and it was visible to anyone who looked carefully. The State’s evidence of impairment was, in substantial part, a physical characteristic he was born with.
The chain that has to hold
There is a second problem, and it is one we see constantly. The standardized field sobriety exercises are only meaningful if they are administered the way the training requires.
The logic is a chain, and every link has to hold. If the officer does not follow the protocol, the test is no longer standardized. If the test is not standardized, it has not been validated. If it has not been validated, the numbers and the clues attached to it do not mean what the State says they mean.
In this case the test was not administered correctly. That is not a technicality invented for trial. It is the entire reason the protocol exists, because the research that gave these exercises any predictive value at all studied them performed one specific way.
The drug recognition witness
The State also called an officer trained as a drug recognition expert.
On cross-examination he did not answer the questions he was asked. He gave long answers on subjects other than the question, and he directed those answers to the jury rather than to the person asking. We let it continue, because a witness who will not answer a plain question is telling the jury something more useful than any answer would have.
Juries notice. In this case one of the jurors had genuine medical training and had studied the physiology of eye movement long before walking into a courtroom. The State’s science was being explained to someone who already knew it.
What the verdict means, and what it does not
A not guilty verdict is not a finding that the officers lied. Nobody in that courtroom accused anyone of dishonesty, and we did not argue it. What the jury decided is narrower and more important: the State’s evidence did not prove impairment beyond a reasonable doubt.
That distinction is the whole of a DUI trial. The question is never whether an officer believed you were impaired. The question is whether the evidence, tested properly, actually establishes it.
If you are facing a DUI built on field exercises
A few things are worth knowing. Tell your lawyer about every medical condition you have, especially anything involving your eyes, your inner ear, your back, or your legs, because a condition you consider unremarkable may be the explanation the State recorded as a clue. Ask whether the exercises were administered the way the training requires, and get the training materials rather than accepting a summary.
Most of all, understand that a roadside test is a piece of evidence to be examined, not a verdict. It can be measured against the standard it was supposed to meet, and sometimes it does not survive that comparison.
A note on this result
This post describes the outcome of one specific case. Every case is different, and prior results do not guarantee or predict a similar outcome in any future case. Nothing here is legal advice, and reading it does not create an attorney-client relationship. If you are facing a DUI charge in Florida, talk to a qualified DUI defense lawyer about the facts of your own situation.
