Oregon DUI law took a turn for the sensible this month. The Oregon Court of Appeals held in Oregon v. Bevan that vertical nystagmus or VGN evidence is improper. VGN is the involuntary jerking of the eyes up and down. Although the test is not validated the same way HGN is, police routinely check for VGN.
When VGN is present, police often testify that the presence indicates extreme amounts of alcohol or that the person has consumed more alcohol than usual. The court of appeals in Bevans ruled that such testimony is improper because it is not backed up with scientific validation.
This result is a welcome turn towards science. In DUI cases, the government often cloaks its testimony in science to make it seem irrefutable. When that science is challenged, the government sometimes claims that such challenges go to the weight of the evidence not its admissibility. This is a classic example of trying to have it both ways.
In this case, the Court of Appeals held the government to a logical position. If the government wants to introduce scientific evidence, that evidence must be based in science. This result should not come as a surprise. There is well established case law laying out the basis for allowing scientific evidence. Far too often, however, it seems that there is an DUI exception to the rules. This case, along with the earlier Court of Appeals case of Machuca, indicate a trend away from this historical unwritten exception.
