Last week, I wrote briefly about a decision from Kansas that may have an effect on how our courts deal with what what is known as the horizontal gaze nystagmus (HGN) test. As the standardized field sobriety tests (SFST) are important for any DUI defendant to understand, I thought I would use this post as an opportunity to explain the HGN in a little more detail.
The SFSTs are approved by the National Highway Safety Administration. They are considered standardized because they are intended to be completed in the same manner each time they are used. The standards supposedly ensure that results are uniform from person to person.
Presently, there are three SFSTs. They are the one-leg stand, the walk and turn, and the HGN. The HGN is, in many ways, the most complicated.
The test itself looks for jerking or bouncing movements in the eyeball when it scans horizontally, which can occur earlier during an eye movement than normal if a person is intoxicated. Officers conduct the test by positioning a pen or finger about a foot from the driver's face and moving it from side to side, while observing the driver's eye movement.
Each eye is tested separately. If the eye begins to oscillate before it has turned 45°, it is a sign that that the driver has blood alcohol content. Officers also look for pronounced jerking at the furthest scanning point, and the ability to follow the object smoothly.
Whether the results of the HGN are admissible in court depends on the state. In some states, the HGN is not admissible at all. Some allow it for limited purposes. Other states allow test results to be admissible for any purpose.
Jurisdictions differ on the admissibility of the test because its accuracy has been challenged; it is unclear if the test is truly indicative of intoxication. One study cited by the Kansas Supreme Court suggested that the HGN gave no true indication of a person's sobriety level.
The Kansas Supreme Court concluded that the trial court erred, requiring that prosecutors must show that the HGN test was reliable to be admissible during a suppression hearing. The trial court had made no requirement that the state show the reliability of the test itself. The conviction was reversed and remanded.
It is always refreshing to see science correctly interpreted in court. Failing an HGN can have a permanent effect on a driver's life; giving that driver the ability to challenge the test's admissibility on objective grounds merely means that the trial process is that much fairer.
If you have been charged with a DUI in and around Seattle in King, Pierce, or Snohomish Counties, you need an experienced attorney who will fight to keep your proceeding fair. If you have been so charged, do not hesitate to contact attorney Kevin Trombold for a free consultation.