FIELD SOBRIETY TESTS – WHAT DO THEY SHOW?

 Posted on June 17, 2022 in Criminal Defense

We’ve all seen TV shows and movies depicting people undergoing roadside sobriety testing; some of us have personally witnessed it. What are they doing? Is it scientific? Does it show whether one is under the influence of alcohol?

I’ve been handling DUI cases for over 30 years. In my opinion, these tests show whether a person can balance and whether one can multi-task. That’s it. What if a person does not do the tests perfectly? Sometimes this is obviously due to being drunk. Other times it is a person who has poor balance, or who has trouble multi-tasking in an anxiety-ridden roadside encounter with an officer who may just take them to jail. 

Officers will commonly ask a person to walk a line. In addition to asking them to walk the line, they will announce other commands: stand in a certain fashion during the directions, don’t attempt the test during the directions, walk heel to toe, for a certain number of steps, keep your arms down at your side, turn in a certain fashion, count out loud, etc. You can walk the line perfectly – but turn in one motion instead of the little motions they told you to do and they’ll count that as one of two strikes; put your arm out more than six inches and that will be the other strike they were looking for. Disobey just two of the commands and they’ll come to court and say that shows you were drunk. In a perfect world, there will be audio and video of this so you can challenge the officer’s report of what occurred. 

Another test is the nystagmus test. In this one, the officer drags his finger or a pen in front of your face and asks you to follow it with your eyes, not moving your head. In theory, he is assessing whether your pupil bounces at a certain “angle of onset” and whether you “don’t track smoothly.” In court, they’ll claim that your eyes showed clues indicating intoxication. In practice, they can say anything they want about this test – even with video running, the camera will not pick up whether you actually had nystagmus-related clues. Officers are free to say what they want here. I’ve had cases where the officer claims he saw all the clues and the blood alcohol test came back .00. Take this test at the risk of not having an honest officer in charge. 

Much time is spent in court analyzing these tests without taking a look at the presumption that performance on these tests actually means something. What do they actually show? Nothing more than balance issues or attention issues. That’s all.  

If you were arrested for driving under the influence, contact Santa Cruz criminal defense attorney John W. Thornton for help. Call our office at 831-426-5800 for a free consultation.