Chapter 6 - § 6.2 • EVIDENCE OF ROADSIDE SOBRIETY TESTS

• Jurisdiction: Colorado

§ 6.2 • EVIDENCE OF ROADSIDE SOBRIETY TESTS

§ 6.2.1—Summary

Evidence of roadside sobriety tests is frequently offered during a DUI trial, usually by the prosecution. These tests are designed to indicate whether a person is affected by the consumption of alcohol or some other substance, and are therefore relevant. Generally, the observations of the testing officer are admissible. CRE 401. Conclusions by the testing officer concerning the meaning of the results of the test may be subject to closer scrutiny, as there is a danger that such opinions may be in the nature of an expert opinion, thus requiring an expert witness foundation. Additionally, some tests, specifically the horizontal gaze nystagmus test, may require a greater foundation than other tests.

Roadside sobriety tests necessarily rest to some extent upon the subjective observations of the testing officer, but they are nonetheless designed to reveal objective information about the driver's coordination, and are "premised on the predictable effects of the consumption of ethyl alcohol: 'Sensitivity is reduced, reaction time is slowed, ability to discriminate is diminished, digital dexterity is reduced, auditory and visual discrimination and judgment fall away, tactile perception is lowered, and speed of motor response drops.'" People v. Ramirez, 609 P.2d 616, 621 (Colo. 1980) (citations omitted).

The Colorado Supreme Court has made it clear that a roadside sobriety test is a "search" in the constitutional sense and must, therefore, be supported by probable cause to believe the defendant was driving under the influence of, or impaired by, alcohol or some other drug, or it must be performed voluntarily. People v. Carlson, 677 P.2d 310, 316-18 (Colo. 1984); see § 4.3. The Colorado Supreme Court has made it equally clear that most roadside sobriety tests do not implicate the privilege against self-incrimination and, therefore, a Miranda warning is not required. Ramirez, 609 P.2d 616. Ramirez cited a myriad of cases from other states that are in accord with this majority view. It cited two federal cases that analogized roadsides to handwriting and voice exemplars as non-testimonial in nature. The exception to this general rule concerns those "test" questions that are designed to test the driver's mental state (i.e., What is the date of your sixth birthday?). Such tests do fall within the protection of the Fifth Amendment. Pennsylvania v. Muniz, 496 U.S. 582 (1990).

The National Highway Traffic Safety Administration (NHTSA) has published material relating to the scientific basis and practical administration of standardized field sobriety tests (SFST). The website is www.nhtsa.gov. These materials serve as a primary basis for the training of police officers in Colorado. SFSTs are now standard pre-arrest procedure for evaluation of DUIs in all 50 states. Colorado was the first state to require periodic refresher training for SFST practitioners and instructors.

The NHTSA believes that three SFSTs are the most reliable: the horizontal gaze nystagmus (HGN), the walk-and-turn, and the one leg stand. These three tests are discussed in more detail in §§ 6.2.2, 6.2.3, and 6.2.4. When these three tests are combined, the NHTSA boasts that officers accurately assess a driver at .08 BAC or above in 91 percent of cases. Other SFSTs are discussed in the succeeding sections. The DUI Enforcement Manual for Colorado was last updated in 2008 and is available through the Colorado State Publications Library Digital Repository at http://hermes.cde.state.co.us. The Colorado DUI manual adds the Rhomberg, alphabet or counting, and the finger-to-nose tests to the three SFSTs recommended by the NHTSA.

Other than HGN, most SFSTs are designed to be "divided attention" tests — that is, tests that require the test subject to concentrate on two or more things at once. Driving is a divided attention task that is composed of many components, including information processing, short-term memory, judgment and decision-making, balance, vision, small muscle control, and coordination. Alcohol (and many other drugs) reduces a person's ability to perform divided attention tasks, so an SFST that tests a person's ability to perform divided attention tasks should be a valid measure of that person's ability to drive safely.

The NHTSA and others have researched the accuracy of the SFSTs, with varying results. For a critical review of the reliability of SFSTs, one can "Google" Dr. Spurgeon Cole, a Clemson University professor who has written dozens of articles critical of SFSTs, and see Fitzgerald, Intoxication Test Evidence § 27:1 (2d ed.). It is clear that the administration of more than one test will improve the accuracy of a conclusion that a suspect is under the influence of, or impaired by, alcohol or other drugs. A thorough discussion of the reliability and admissibility of roadside sobriety tests occurs in U.S. v. Horn, 185 F. Supp. 2d 530 (D. Md. 2002). A handful of states have declined to follow or extend Horn.

A demonstration of the roadside sobriety maneuvers is within the discretion of the trial court. People v. Evans, 987 P.2d 845 (Colo. App. 1998) (overruled on other grounds), contains the following language:

Because a reenactment of events can be highly persuasive, a trial court must take special care to ensure that the reenactment fairly depicts the events at issue. However, the test for admission of reenactments does not require identity, but only substantial similarity, of conditions of the actual event and the reenactment. Minor variances affect weight rather than admissibility. The decision to admit a reenactment is within the sound discretion of the trial court, and will not be reversed absent an abuse of discretion.

Id. at 852; see also People v. Agado, 964 P.2d 565 (Colo. App. 1998).

§ 6.2.2—Horizontal Gaze Nystagmus

Nystagmus is an involuntary jerking of the eyes. Horizontal gaze nystagmus (HGN) is the jerking that occurs naturally as the eyes gaze to one side or the other. Normally, HGN occurs only when the eye is looking at a high peripheral angle. Generally, people are not even aware that nystagmus is occurring and cannot stop or control it. Alcohol impairment tends to cause nystagmus to occur at a lesser angle, and also causes the jerking to be exaggerated at the maximum angle.

In an HGN test, the officer observes the eyes of the test subject as the subject follows a small object that is moved back and forth across the subject's field of vision at eye level. The subject is instructed to follow the object with his or her eyes while keeping his or her head still. Thus, a third aspect of the HGN test is that it measures the subject's ability to track an object smoothly as the officer moves it. The testing officer should first check the subject's eyes for equal tracking ability and equal pupil size to reduce the chance that a medical disorder or injury is causing the nystagmus.

A properly conducted test requires the testing officer to tell the subject to:

1) Remove eyeglasses (and determine whether contact lenses are in use);
2) Place feet together, with hands at sides;
3) Keep head still;
4) Focus eyes on the specific stimulus;
5) Follow the movement of the stimulus with the eyes only; and
6) Keep focusing on the stimulus until told that the test is concluded.

The testing officer should use a small object such as a pen, small flashlight, pencil eraser, or even a fingertip as the stimulus; position the stimulus approximately 12 to 15 inches in front of the subject's nose; move that object back and forth, slowly, steadily and horizontally, in front of the subject slightly above eye level. "Slowly" in this context means that it should take about two seconds to move the stimulus from the center position to the extreme position. The stimulus should be held in the extreme position for approximately four seconds.

The testing officer should watch each of the subject's eyes, beginning with the left eye. The testing officer should determine whether (1) the eye is tracking the object smoothly, (2) nystagmus occurs in the eye before the eye reaches 45° from center, and (3) the nystagmus is distinct once the eye reaches maximum deviation for a few seconds. If the stimulus is 12 to 15 inches in front of the subject's nose, 45° will be reached when the stimulus has been moved about 15 inches to the side. The testing officer should make these determinations in this order.

There are three clues for each eye, or a total of six clues. NHTSA research (by Stuster and Burns, 1998) concludes that a suspect who shows four or more clues likely has a BAC of .08 percent or greater. The reliability of this conclusion is 88 percent. These clues may also indicate the ingestion of a variety of other drugs, specifically including central nervous system (CNS) depressants, inhalants, PCP, and anti-seizure medications.

Nystagmus may be caused by other factors, including rapid spinning, disturbances of the inner ear and the fluid in the inner ear, and certain visual activities. NHTSA research indicates that these factors will not influence a properly administered HGN test. While it is possible that the reactions of the eyes of someone who is under the influence of alcohol will react in a significantly different fashion, such a result is unlikely. If such a result does occur, it is likely evidence that the test subject is suffering from a pathological disorder that causes such a result or that the officer's observations were not accurate.

Colorado appellate courts have now recognized the admissibility of HGN evidence, without need for a Shreck hearing, in People v. Marston, 2020 COA 121. In Marston, the court recognized, "The weight of judicial authority therefore favors admissibility of HGN test results without the need for additional evidence of scientific reliability — at least if...