Section 20.36 Field Sobriety Tests—Horizontal Gaze Nystagmus

• Library: Evidence 2017

F. (§20.36) Field Sobriety Tests—Horizontal Gaze Nystagmus

In State v. Hill, 865 S.W.2d 702, 704 (Mo. App. W.D. 1993), overruled on other grounds by State v. Carson, 941 S.W.2d 518, 523 (Mo. banc 1997), the court found that the HGN (Horizontal Gaze Nystagmus) test “has achieved general acceptance within the behavioral science community.” HGN evidence may be admitted without first obtaining expert testimony regarding the HGN test’s scientific validity, provided that an appropriate foundation is laid. State v. Rose, 86 S.W.3d 90 (Mo. App. W.D. 2002).

Although HGN test results are admissible as circumstantial evidence of intoxication, the HGN test score does not create a presumption of intoxication. Id. at 98. The ultimate conclusion rests with the trier of fact, who is free to believe or disbelieve the officer’s testimony and to ascribe the weight given to it. Id.

Before an officer can state an opinion as to the driver’s performance on the HGN test, an adequate foundation must be established consisting of a showing that (1) the officer is adequately trained...