SFST’s or Chemical Tests – Important Legal Differences
As an important first point — there is a legal distinction between “standardized field sobriety tests” and a chemical test of breath, blood, or urine in the context of a DUI investigation. Utah law includes an “implied consent” provision that allows police to request a “chemical” test for the detection of alcohol, drugs, or controlled substances if the officer has reason to believe that a person is driving under the influence. Utah law further provides for suspension of a driver’s license if the driver refuses to submit to such chemical testing when requested by an officer.
This article does not address “chemical” testing, but instead discusses a person’s right to refuse to perform “standardized field sobriety tests” as part of a traffic stop or DUI investigation. If you have any questions about your rights or obligations under the law, consultation with a good attorney is strongly advised.
What are standardized field sobriety tests?
The National Highway Transportation Safety Administration (NHTSA) provides training and guidelines for police officers conducting DUI investigations. This training includes what have become referred to as “standardized field sobriety tests” or “SFST’s.”
Historically, police used a variety of “tests” in the field to attempt to determine whether a driver was intoxicated or under the influence of alcohol or drugs. Such tests included asking a driver to touch their nose with their eyes closed, to recite the alphabet in reverse order, to touch the tips of each finger on one hand using the index finger of the other hand, or to perform other similar tasks or tricks. The biggest problem with these “tests” was that there was no scientifically validated way to interpret the results.
To address this lack of scientific validity, researchers conducted several studies in an attempt to identify tests that could be easily done “in the field” (prior to an arrest) that could be used to support probable cause to arrest a driver for DUI. Once a driver is arrested, police are then able to conduct more reliable chemical testing to detect the presence (or absence) of alcohol, controlled substances or metabolites in the driver’s blood, breath, or urine.
Three tests identified by researchers as having better correlations with the presence of alcohol in a person’s system. These tests are:
- Horizontal Gaze Nystagmus (HGN)
- 9-Step Walk-and-Turn (WAT)
- One Leg Stand (OLS)
There are concerns with and is some dispute as to the soundness of the research studies used to “validate” the accuracy of these tests. However, a discussion of the exact nature of these tests and the concerns surrounding them is beyond the scope of this article.
Can a Utah driver refuse to perform SFST’s?
Under Utah law, performing field sobriety tests at the direction of a police officer falls under the search and seizure protections of the Fourth Amendment. A police officer who has good reason to suspect a driver may be DUI can ask the driver to perform field sobriety testing. But the police officer does not have authority to order the driver to perform the testing.
As noted above, Utah’s implied consent laws provide for extended driver license suspension if a driver refuses to submit to chemical testing (blood, breath, or urine) when an officer has reason to believe the person is driving under the influence. But the implied consent laws do not apply to non-chemical field sobriety testing procedures.
There are a number of perfectly legal reasons that a person might choose to decline an officer’s invitation to perform field sobriety tests. Some officers may phrase their “invitation” to do SFST’s in a way that feels more like a command. If the officer’s invitation is unclear, a person should be able to ask the officer to clarify whether the officer is ordering the person to perform the tests or if the person is instead free to refuse.
As a general rule, if an officer tells a person that they are being ordered to do something, it is best to comply with that order. But in most circumstances, if an officer asks someone to perform field sobriety tests, the person should be free to refuse.
Can a prosecutor use a refusal as evidence at trial if a DUI charge is filed?
Because a driver is under no obligation to perform the standardized field sobriety tests (horizontal gaze nystagmus, walk-and-turn, one-legged stand), a prosecutor normally should not be able to use the refusal itself against a person charged. However, the person’s conduct and demeanor in making the refusal may be admissible in court if criminal charges are filed against the person.
Prosecutors can argue that belligerence, shouting, foul language, and other such conduct is an indication of possible intoxication. Slurred speech, difficulty standing upright, and bloodshot eyes can also be used as an indicator that the person is under the influence of drugs or alcohol.
In general, no single such factor taken in isolation would, by itself, constitute probable cause to arrest, judges and juries often consider the totality of the circumstances in making decisions and reaching verdicts. While the refusal itself may not be admissible, other actions and statements may be used against you.
