Illinois Supreme Court Questions Reliability of a Field Sobriety Test

The Illinois Supreme Court issued a ruling in September in the case of Illinois v. McKown that questioned the use of a key field sobriety test known as the horizontal gaze nystagmus (HGN). The court ruled that the results of a horizontal gaze nystagmus test should be subject to challenge at trial. A prior Court of Appeal ruling had determined that the reliability of the test could not be questioned at trial. In overruling the Court of Appeal, the Illinois Supreme Court noted that there is a difference in opinion in courts across the country as to whether the HGN is reliable. The court previously noted that the National Highway Traffic Safety Administration (NHTSA) has determined that the test is incorrect 22 percent of the time.

The HGN is one out of a battery of three tests developed by the NHTSA to assist a police officer in obtaining validated indicators of impairment and establish probable cause for an arrest. These three tests are referred to as the Standardized Field Sobriety Test (SFST), and consist of the HGN, the walk and turn, and the one-leg stand.

The HGN test measures the extent that your eyes flicker back and forth while following a moving object such as a pen, a finger, or a small flashlight. The theory behind this test is that someone under the influence of alcohol will have difficulty following the object and that the eye flicker will occur early, while a person who is not under the influence will be able to track the object further. However, HGN test may indicate other substances besides alcohol such as seizure medications, phencyclidine, a variety of inhalants, barbiturates, and other depressants.

In the McKown case, Joanne McKown was involved in an accident involving her vehicle and three motorcycles. Ms. McKown admitted to having two beers before leaving her home and a third while driving. Ms. McKown was transported a hospital for treatment for a broken toe. While in a hospital bed, an officer administered the HGN test, which he determined Ms. McKown failed. No other field sobriety test was administered, since Ms. McKown had a broken toe and could not walk properly. The officer admitted that he knew McKown had been administered medication while in the hospital, drugs that could have affected the HGN results.

Ms. McKown was charged with multiple counts of DUI and reckless driving. She refused to submit to chemical testing until a search warrant was issued several hours later. Blood samples taken from McKown did not detect the presence of any alcohol, and the only evidence of her impairment was the failed HGN test.

The Illinois Supreme Court did not find McKown to be innocent of the charges; rather, it determined that an evidentiary hearing must be conducted to establish the reliability of the HGN test. The case was therefore remanded back to the trial court.

If you are arrested for a DUI in Illinois, you must contact an attorney immediately.
A lawyer experienced in defending people accused of DUI can challenge the prosecutor’s evidence and could have the charges reduced or dropped without having to accept a conviction. Thanks for reading my blog. If you have a comment or question, feel free to post it here, but keep in mind your posting will not be confidential. If you have been accused of DUI in Illinois, call or e-mail me for immediate assistance.