In Schultz, the defendant was stopped for suspicion of driving under the influence. The officer approached the defendant’s car and requested that he perform several field sobriety tests including the horizontal gaze nystagmus test. At trial, the officer was permitted to testify that the defendant failed the HGN test. However, the defendant appealed, arguing that this testimony should not have been permitted because the HGN test is a scientific test and testimony regarding scientific tests can only be offered by an expert.
The court found that the HGN test was a scientific test and that the test was generally reliable. However, in this particular case, the officer was not properly trained as an expert and his testimony was therefore inadmissible. The court reasoned that when the HGN test is not performed correctly, the results are not reliable. In fact, there are at least 38 other causes of nystagmus including: (1) problems with the inner ear labyrinth; (2) irrigating the ears with warm or cold water under peculiar weather conditions; (3) influenza; (4) streptococcus infection; (5) vertigo; (6) measles; (7) syphilis; (8) arterioscle¬rosis; (9) muscular dystrophy; (10) multiple sclerosis; (11) Korchaff's syndrome; (12) brain hemorrhage; (13) epilepsy; (14) hypertension; (15) motion sickness; (16) sunstroke; (17) eye strain; (18) eye muscle fatigue; (19) glaucoma; (20) changes in atmospheric pressure; (21) consumption of excessive amounts of caffeine; (22) excessive exposure to nicotine; (23) aspirin; (24) circadian rhythms; (25) acute trauma to the head; (26) chronic trauma to the head; (27) some prescription drugs, tranquilizers, pain medications, anti-convulsants; (28) barbiturates; (29) disorders of the vestibular apparatus and brain stem; (30) cerebellum dysfunction; (31) heredity; (32) diet; (33) toxins; (34) exposure to solvents, PCBS, dry cleaning fumes, carbon monoxide; (34) extreme chilling; (35) eye muscle imbalance; (36) lesions; (37) continuous movement of the visual field past the eyes, i.e.,looking from a moving train; (38) antihistamine use.
Schultz v. State of Maryland is among the most cited cases by DUI defense lawyers across the nation. The case is particularly useful for undermining the validity of the horizontal gaze nystagmus test. However, in Colorado, the appellate courts have not ruled on the issue of whether or not the HGN test is a scientific test. In addition, the Colorado courts have not examined whether the HGN is generally reliable. Until such a decision is issued, the status of the HGN in Colorado will remain uncertain.
