When conducting a traffic stop for a suspected DUI, police officers have many tools at their disposal. Although their efficacy and probative value is arguable, Field Sobriety Tests provide officers many avenues to collect evidence from defendants suspected of driving under the influence. One of the most commonly used “roadside tests” is the Horizontal Gaze Nystagmus, or HGN. When administering the HGN, officers will direct an individual to follow his or her finger with their eyes, training the eyes back and forth across a plane to detect movement, straining, or other signs within the eyes meant to evidence impairment. Despite some objections, HGN “has reached a state of verifiable certainty in the scientific community and is admissible as [evidence] that a driver [is] impaired by alcohol.” Hawkins v. State, 223 Ga. App. 34 (1996).
The problem arises when officers and DUI prosecutors try to use HGN results to prove something more beyond mere evidence of impairment. In Spencer v. State, S16G1751 (Oct. 2017), an officer administered the HGN exam prior to making a DUI arrest. However, at the later trial, the officer testified that the “four out of six” clues he observed during the HGN “indicates an alcohol concentration equal to or greater than a .08.” Not only was the officer trying to use HGN results to show evidence of impairment, but also that such results indicated a specific blood alcohol content in excess of Georgia’s legal limit.
The Georgia Supreme Court found that such use of HGN results was a bridge too far. Noting that the use of “HGN test to identify a specific numeric BAC has not ‘been recognized in court as reaching the requisite scientific stage of verifiable certainty,’” the Court found that the officer’s testimony in Spencer was improper. The officer had no medical or scientific training to be able to draw a correlation between HGN results and a specific BAC level and, although courts in Georgia allow HGN to show signs of impairment, speculating on specific levels of impairment, without relevant scientific data to support the conclusion, is unacceptable. As such, the Court reversed Spencer’s DUI conviction.
It often feels like the deck is stacked against citizens during DUI investigations and prosecutions. The law gives great authority to officers during DUI stops and the remedies and rights of individuals in those situations can, at times, feel negligible. Nevertheless, the authorities’ powers are not without limit. Field Sobriety Tests are designed for specific, limited uses and stretching those tests’ results beyond what they are intended to provide is unacceptable. HGN can show general signs of impairment but never, without more, specific levels of blood alcohol content. Joel Davis and Lincoln Jones are experienced DUI attorneys are if you or somebody you know has recently been involved with a DUI stop and potential arrest, please call us so that we can make sure your rights are protected during the entire process.
To read the full Spencer opinion, click here.