The Supreme Court of Illinois has recently issued a definitive opinion regarding the HGN test: Illinois v. McKown
In the McKown case that Court found the following:
1. The HGN field test was originally developed by Burns and others as a tool to screen drivers to determine whether blood-alcohol concentration testing was justified. The test was not designed to determine whether the subject is impaired for driving and its use for this purpose has not been validated by controlled studies. Further, Rubenzer asserts that the developers of the test, along with prosecutors, have “oversold” the test.
2. In the 1970s, NHTSA sponsored research by psychologist Dr. Marcelline Burns of the Southern California Research Institute into the reliability of field-sobriety testing. Based on her research, which found a correlation between the ingestion of
alcohol and the presence of HGN, law enforcement agencies adopted this clinical test for use as a field-sobriety test.
3. The question of general acceptance must be determined from the testimony of experts and the literature in these scientific fields [ophthalmology, and optometry] and not from the testimony or writings of law enforcement officers or agencies.
4. We, therefore, adopt the trial court’s finding that HGN testing is generally accepted in the relevant scientific fields and that evidence of HGN test results is admissible for the purpose of proving that a defendant may have consumed alcohol and may, as a result, be impaired.
5. We hold that evidence of HGN field-sobriety testing, when performed according to the NHTSA protocol by a properly trained officer, is admissible under the Frye test for the purpose of showing whether the subject has likely consumed alcohol and may be impaired.
6. In sum, we adopt the trial court’s findings on remand that HGN testing is generally accepted in the relevant scientific fields as evidence of alcohol consumption and possible impairment. We also adopt the trial court’s five conclusions of law regarding the admission of HGN evidence and its use at trial. The admissibility of HGN evidence in an individual case will depend on the State’s ability to lay a proper foundation and to demonstrate the qualifications of its witness, subject to the balancing of probative value with the risk of unfair prejudice.We find that admission of the officer’s testimony regarding HGN
testing in this case was reversible error. Thus, we reverse the judgments of the appellate and circuit courts and remand the cause to the circuit court for a new trial.
The McKown opinion defintively finds that the HGN test is limited to evidence of the consumption of alcohol and possible impairment; anything more is JUNK science.