NH Field Sobriety Test – When a person is pulled over for DUI, they’re generally asked to perform some tests to “prove their sobriety.” These are three tests approved for use in court, and they are all purely voluntary (even though most people don’t realize it).
The first two tests are very familiar: the walk-and-turn, and the one-legged stand. These tests are just as their names imply. But the third test is the Horizontal Gaze Nystagmus (HGN) test. This is the little game where the police wave a pen in front of your face. It’s named for the phenomenon that causes your eyeballs to jiggle when put into motion. The theory is that the greater the presence of a CNS depressant in your system (such as alcohol), the more jiggly your eyeballs become. It’s a very important tool for police in DUI trials on account of the fact that no one other than the officer will know if the testimony about the jiggly eyeballs is truthful because the officer is the only one that can see it.
The use of this test developed from studies done back in the 70s. Researchers published experiments claiming to allow police to determine someone’s blood alcohol level (BAC) as being over 0.10 if they notice enough different ways that their eyeballs jiggle. The research claimed that if the eyeballs jiggled four out of six ways, then there was a 77% chance that the person was over the limit.
Some years later, courts began accepting this test in trials, but not without limitations. New Hampshire, for example, allowed the police to present the results of the test as an indicator that someone was impaired by alcohol, but not to determine the specific blood alcohol content. Keep in mind that it was in 2002, and has been the controlling law since.
In 2007, researchers did a review of the science to show how “robust” it was. But, as it happens, one of the leading scientists recently challenged his own findings. He found that the methods used to get the original studies were not reliable and could not have produced the results that they did. This new literature has given DUI defense attorneys a long-awaited means of challenging the introduction of HGN evidence at trial.
This is just one of the many issues that make a DUI case so complicated. If you’ve been charged with impaired driving, you need experienced counsel to give your case a thorough review. Give us a call at (603) 288-1403 to get started or fill out our online contact form.