Hermosa Beach DUI Lawyer Explains HGN Law in Drunk Driving Cases

In California, police officers in the field have many different "tests" at their disposal to ascertain whether a suspect is DUI. One of the field sobriety tests that the officer may administer is the horizontal gaze nystagmus (HGN) test. The test involves having the suspect follow a moving object with his or her eyes, then measuring the angle of onset at which an involuntary jerking or "bouncing" of the eyes begin. One local Hermosa Beach DUI Lawyer relates that,  Depending on the observations of the DUI police investigator at the angle of onset, the prosecution may argue that the failure of the drunk driving suspect to follow the object or a jerking of the eyes may be consistent with the presence of alcohol and/or some types of drugs. The individual cop's observations may be admitted as evidence of the presence of alcohol, as will the officer’s opinion, based on the Nystagmus test in combination with other tests, that the defendant was under the influence. The officer’s testimony, however, should not draw a correlation between the HGN test and any specific blood-alcohol level. The CA Appellate Courts have ruled that HGN evidence, when viewed with other relevant indications, meets Kelly-Frye standard for general acceptance in the scientific community for purposes of deciding whether a person is under the influence of alcohol.