Motorists pulled over on suspicion of a DUI usually are given a battery of tests so that officers may collect evidence. The test in which an officer shines a flashlight near one's eye and asks the subject to gaze to the side is called the horizontal gaze nystagmus test (HGN), as explained by the National Highway Transportation Safety Administration.
Essentially, the test is based on the fact that alcohol impairment hinders the brain's ability to smoothly control a person's eye muscles.
But the importance of the HGN test in determining intoxication was greatly minimized by the Illinois Supreme Court in a case closely watched by Illinois DUI lawyers.
The Peoria Journal-Star covered the Feb. 19 ruling that found the test "generally accepted in the relevant scientific fields as evidence of alcohol consumption and possible impairment." Justices ruled unanimously in the case, People v. McKown (PDF).
Justice Rita Garman wrote the opinion and generally held that HGN only can be used to show the possibility of impairment and not conclusive evidence of intoxication. The HGN test in Illinois is no longer considered proof of actual impairment as it does not prove a BAC of 0.08 percent or greater and must be considered on a case-by-case basis.
Defendant Joanne McKown was involved in a 2002 accident where she collided with three motorcycles, according to the Peoria Journal-Star. A witness said he smelled beer on Ms. McKown's breath, while an officer said he smelled beer in her car and found an empty beer can.
The officer found no further evidence and conducted the HGN test on Ms. McKown at the hospital, which she failed. A blood test was conducted a few hours after the incident, showing no alcohol in her system. She was convicted in a bench trial and sentenced to two years in prison.
Her case was remanded (or sent back) to the trial court.
Related Resources:
-
What are Field Sobriety Tests? (FindLaw)
-
Illinois Ups the Ante for First-Time DUI Offenders (FindLaw KnowledgeBase)
-
Directory of Chicago DUI Lawyers (FindLaw)
