HGN, the Rules of Evidence and Suppression Hearings

True or False:  An officer does not have to be qualified as an expert to testify about horizontal gaze nystagmus in a hearing on a motion to suppress in an impaired driving case. This statement is true. Say what? I’ve written a lot about expert testimony and horizontal gaze nystagmus (HGN) lately, including a post titled “Only Experts Can Testify about HGN.” That post describes the court of appeals’ determination in State v. Godwin, ___ N.C. App. ___ (2016), that N.C. Evid. Rule 702(a1) requires a witness to be qualified as an expert before he may testify to the issue of impairment related to HGN results. But Godwin states the rule that applies to the admission of testimony at trial.  The rules are different at a hearing on a motion to suppress. How does this issue arise? The HGN test is one of three standardized field sobriety tests that law enforcement officers frequently ask drivers suspected of impaired driving to perform. Thus, an officer’s observation of clues on the HGN test often is relevant to determining whether there was probable cause to arrest the defendant for impaired driving. When an officer attempts to provide such testimony in a suppression hearing, defense attorneys sometimes object on the basis that the officer lacks the requisite expertise or the reported results are unreliable. What’s the law? Rule 104(a) of the North Carolina Rules of Evidence states that in determining preliminary questions of admissibility—the very issue in a suppression hearing—the court is not bound by [...]