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  • Writer's pictureBrian Foley

Conroe DWI Lawyer - What is the least persuasive filed sobriety test? Montgomery County, Texas

Conroe and Montgomery County DWI lawyer Brian Foley Explains the field sobriety test least likely to convince a jury.

After trying many cases of DWI one thing becomes clear. Most members of a jury base their decisions on an emotional sense they have of the case early on and this is aided by the presentation of evidence and the jury selection process completed by the lawyers. However the second most important part of a DWI case is the video which probably shows the completion of the filed sobriety Tests.

There are three standardized field sobriety tests given by police all across the county over the last 40 years. They have remained significantly unchanged during that time.

The first such test is called the HGN which stands for Horizontal Gaze Nystagmus, it is a test where the police officer is looking for three different "clues" in the right and left eye of a citizen accused of DWI. The clue is "nystagmus" or the involuntary jerking of the eye which allegedly occurs because of intoxication and the intoxicating substance's effect on the small muscles which control eye movement.

The second test is called the W&T or Walk and Turn. It is a test that requires the subject to take 9 heel to toe steps in a straight line and on their ninth step leave their lead foot planted and turn around using a series of small steps and take 9 steps back along the same real or imaginary line.

The third test is called the OLS or One Leg Stand. It is a test that requires the subject to raise a foot of their choosing approximately six inches off the ground leaving their arms to their side and count in a manner proscribed by the officer, typically 1001, 1002, and so on until the officer tells them to stop.

So which of these tests is least likely to convince a jury that you are intoxicated? Its the HGN. I've heard other defense attorney's say that HGN stands for "Here goes nothing." People believe what they can see for themselves. And the HGN is the least likely test to be captured on video. Even when it is captured on video people are unfamiliar with the language "nystagmus" and have pretty much never heard or seen its effect on eye movement.

Interestingly enough it is the most relied upon test for Officers in the field which frequently say that it is the most reliable measure of if someone is intoxicated because no matter what your tolerance level for alcohol you cannot control the small muscles in your eye from involuntarily jerking. Even so it is difficult for the State through officers and prosecutors to make the case for HGN. Having an experienced Defense attorney on your side to question the way that the test was administered and if the proper timing, spacing, and movements were made by the officer conducting the test can also help you make the case that you are not guilty.

Jurors put much more faith in the walk and turn and one leg stand tests as they are performed on video. Typically jurors will have had some familiarity with seeing someone walk or stand while intoxicated and they will compare what they see on video to their own life experience.


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