Nystagmus as part of DUI investigation, Los Angeles
Nystagmus is an investigation tool used by law enforcement to determine if a person is under the influence of alcohol. After a DUI stop, a police officer, if he suspects that the driver is under the influence of alcohol, can ask the driver to step out of the vehicle and submit to field sobriety tests. The field sobriety tests are voluntary tests that drivers suspected of DUI in Los Angeles can and should decline to perform. If you agree to do the field sobriety tests, the cops and the DA will use them to show that you are impaired. The tests are highly subjective and can cause a person to be arrested even when he or she is not under the influence of alcohol and drugs and he is not DUI.
The most common field sobriety tests are known as Standardized tests and are, a horizontal gaze nystagmus test (HGN), a walk-and-turn test (WAT), a one-leg-stand test (OLS), and a preliminary alcohol screening test (PAS test).
During a Los Angeles DUI investigation, police officers will look in the eyes of a driver to see if his eyes jerk. This is known as a test for nystagmus and for alcohol impairment, Los Angeles DUI investigating officers will ask you to follow an object with your eyes only to test the presence of horizontal nystagmus. This test is not always accurate and shows the presence of alcohol in approximately 77% of people. A horizontal gaze nystagmus test is a “standardized” test because it is administered the same way with the officer looking for up to 6 clues (with 2 clues indicating impairment). The test was based on a 1975 study to determine how accurately can police officers approximate the number of people who would be under the influence of alcohol. The same study also gave law enforcement other 2 standardized tests, the Walk and Turn Test and the One-Leg-Stand Test. The validity of the 1975 study was confirmed with “validation studies” in 1995, 1997, and 1998 in Colorado and Florida. The California CHP manual states that the use of these three tests will allow the officer to determine with 90% accuracy if someone is under the influence of alcohol. Having DUI police do standardized field sobriety tests can be a problem because the cops will say that they are very accurate and scientifically tested
However, a DUI officer who decides to give you a horizontal gaze nystagmus test must be trained in the administration of the test. If the test is not performed according to the standard criteria, the test can not be deemed valid. For example, during the nystagmus test, the subject of the test should take his glasses off and the stimulus used to administer the test should be kept at 12-15 inches from the nose of the subject. If the officer does not follow these instructions, the test, even if nystagmus is observed, is worthless. During the nystagmus test, the officer will attempt to observe the tracking ability of the eyes, the size of the pupils, the lack of smooth pursuit (if any), if the distinct nystagmus is present at the maximum deviation, and if the nystagmus starts prior to the 45% angle.
The officer will look for 6 validated clues to determine if a person is impaired. If 4 out of 6 clues are present, the test is considered to be 77% accurate in determining that a person is above a .10% BAC level. The case law, however, does not allow an officer to testify that the presence of nystagmus can be correlated to a specific alcohol level (People v. Loomis). But 77% accuracy means that 23% of people, or almost 1 in every 4 people, who have nystagmus will not be under the influence of alcohol. Nystagmus can be a neurological condition, be present during the flu, or just present in some people at all times unrelated to any alcohol consumption. Also, often you can see an HGN done too fast. Property done HGN should take 82 seconds.
If you are arrested for a DUI, please call (818) 921 7744 DUI Attorney Los Angeles to talk to someone who is qualified to help you defend your case. Los Angeles DUI attorney is known for his dedication to his clients and his ability to get the best results for his clients in the most desperate situations. We offer great payment plans and can help you not only in court but also at the DMV. Our top Los Angeles DUI lawyer is able to provide quality defense at an affordable price. Call now to talk to a Los Angeles DUI attorney about your case.
(No Ratings Yet)
Loading...