or a free consultation with a Missouri DWI / DUI attorney, call The Law Offices of Benjamin Arnold at (913) 777-HELP, or visit us on the web at kcdui.com.

The Purpose of Field Sobriety Tests

Standardized field sobriety tests, or SFSTs, are used by law enforcement officers nationwide to assist in detecting impaired motorists and gathering evidence to be used to form probable cause to make an arrest. These tests are standardized, in that for the most part they are uniformly followed by agencies across the country. The tests are issued in accordance with guidelines from the National Highway Traffic Safety Administration (NHTSA). To form probable cause for an arrest, an officer must make note of any clues or cues which have been found to indicate impairment.

There are over 100 cues as of today, and the officer must refer to his training to determine whether a driver’s mannerisms qualify as being consistent with impairment. These include behaviors and observations such as an unsteady gait, the odor of alcohol coming from breath, ruffled clothing, handing the officer some card other than your drivers license, etc. The NHTSA has published a manual which contains almost 600 pages, specifically detailing the steps involved in investigating DUI. Officers receive a certification for having passed a course on these methods, and are subject to refresher courses every so often. While in today’s world, these tests are often caught on dash camera or body cam, a solid defense attorney will be well versed in the tests and cross-examine the officer on his knowledge and administration of the SFSTs.

The Three Most Common Tests

Today, there are three standardized field sobriety tests which are regarded as most reliable in determining impairment- the horizontal gaze nystagmus, the one-leg stand, and the walk-and-turn test. The tests you see on TV- counting backwards, the ABC’s, etc. are not as commonly used. It is important to note that it is within your rights to refuse the field sobriety tests, and that implied consent only applies to the “official” test, which is a breath or blood sample taken at the police station or a hospital. The roadside breathalyzer, known as a portable breath test (PBT) is not admissible to prove the level of intoxication in court, but may be used in forming probable cause to make a DUI arrest.

Horizontal Gaze Nystagmus (HGN)

The HGN test is often the first administered, and is regarded as the most accurate test in determining impairment. This test consists of checking the drivers’ eyes by having them follow the movement of an object such as a pen without turning their head. The officer will hold an object approximately 12″ from the subject, and instruct them to follow it with their eyes only.

During this process, the officer will check for nystagmus, which is twitching or involuntary movement of the pupils. The officer will check for “smooth pursuit” or the ability of the eyes to smoothly follow along with the movement of the object. A person who is intoxicated will be unable to exhibit this smooth pursuit, and their pupils will twitch in following the object. Specifically, an indication of impairment is the observation of nystagmus at or before 45 degrees. Other times, people will move their head, or ignore the instructions completely. Someone who has an issue with their vision may be able to raise a potential defense, but the police generally will ask about vision prior to the tests to minimize the risk of this defense being available in court.

Walk and Turn (WAT)

The walk-and-turn test is probably one you have seen on television- during this test, the individual is given instructions to walk 9 steps in a straight line, then turn and make another 9 steps. During the instructions of the test, a common police tactic is to confuse the person with what the instructions are what I like to call the “3 step trick”.

As with the other tests, the officer will first give the instructions and ask whether the person understands. With the WAT, the officer will often offer to do a demonstration immediately after confirming the subject understood the test. When they give their demonstration, they will do something along the lines only taking 3 steps while saying ”and then so on” instead of taking the full 9 steps. After giving the demonstration, they ask a second time whether subject understands them. More often than not, the subject will disregard the prior instruction to take 9 steps, and take 3 steps, then turn. The officer then explains they aren’t doing the test properly and has the opportunity to triple down and ask the person for the third time whether they understand the instructions.

People who are in decent shape will often be able to walk in a straight line, but the way in which the demonstration is given following the instructions will be what throws them off. The police officer will usually act nice and continue to give the subject a couple more opportunities to further incriminate themselves with botched test attempts, even giving additional demonstrations to further confuse them. This test is seem as a good indicator of intoxication because it tests the driver’s ability to follow instructions and focus on a task while processing information, which assesses their ability to respond to road and traffic conditions.

One Leg Stand (OLS)

The one-leg stand is a test that is exactly as it sounds- the officer will instruct the subject to raise one foot approximately six inches off the ground and hold it there for about 30 seconds. During this time, the individual must keep their balance without holding their hands out to the side or touching their raised foot to the ground.

Understandably, a lot of people will fail this test, which is hard for some people to do sober. The officers will likely help build their case by confirming any physical conditions prior to the test. It is important to understand the right to reject these tests, because they are not designed for you to pass, and agreeing to do them will only help the police gather evidence to be used in making an arrest. Of the three tests, this one seems to be the least favored, likely because it relies more on the physical condition of the driver, which can be attributable to many things other than alcohol impairment.

Drug Recognition Experts (DRE)

Most police agencies have many officers certified and trained to administer field sobriety tests, but often will only have a few which are certified as drug recognition experts. A drug recognition expert is an officer with specialized training to detect drug use based on the performance of SFSTs and other behaviors observed during a DUI investigation. Typically, a DRE will be called to the scene if officers believe a subject is impaired, but there is no indication of alcohol, whether it be the lack of odor of an alcohol beverage or a negative breath sample. Of course, the presence of drugs will be revealed in a blood sample, but having a DRE can significantly assist the police in gathering probable cause for an arrest if the subject performs somewhat on the line during the FSTs or in the event they are refused. The use of DREs is becoming more common as more states legalize marijuana, because prosecuting such a case with blood evidence alone may prove difficult as state legislatures are learning what levels indicate impairment at the time of driving.

What is Implied Consent?

In this context, implied consent is agreeing to provide a sample of bodily fluids if you are suspected of operating a motor vehicle while intoxicated. Everyone who signs for a Kansas or Missouri drivers license agrees to this, which in signing you also agree that failure to provide a sample will result in the automatic suspension of your driving privileges.

It is a common misconception that the implied consent law applies to the field sobriety tests- it does not. Implied consent applies only to the ”official” breath or blood tests administered at the police station or hospital. You will also be read and confirmed to have understood a formal document explaining implied consent and the consequences of refusal. It is important to understand that the suspension of driving privileges due to failure or refusal of a chemical test is automatic after 30 days which can be extended by filing a timely appeal. It is wise to hire a Kansas City, Missouri DUI lawyer or a criminal defense attorney to handle this administration hearing; you have only 14 days in Kansas and 15 days in Missouri to preserve your rights on appeal.

Recent SFST Caselaw

*For educational purposes only, and does not constitute legal advice. As the law is constantly changing, these holdings could eventually be overruled. If you have an attorney, consult with that attorney. If you do not have an attorney, give my office a call at (913) 777-HELP or visit us on the web at kcdui.com.

The Presence of Bloodshot Eyes along with the Odor of Alcohol is Insufficient for Probable Cause

The driver successfully argued that his bloodshot eyes were attributable to fatigue, and the odor of alcohol was from the night before. The Western District Court of Appeals found that based on these observations, with no additional evidence there was not an insufficient showing of probable cause for an arrest. After reading the discussion of the tests in section II, do you think the driver exercised his right to decline the field sobriety tests?
Rocha v. Director of Revenue, 557 S.W.3d 324 (Mo. Ct. App. W.D. 2018)

Portable Breath Test Admissible for Limited Purposes

If you read this article closely, perhaps this holding seems to be inconsistent with what I said about the preliminary breath test being inadmissible. This is how nuanced the law can be; the test result is inadmissible as evidence of blood alcohol content, but is admissible as evidence of probable cause to make an arrest and as exculpatory evidence. The court clarified that the actual numerical value of the test may be used in establishing probable cause, and not merely a “positive” or ”negative” indication due to the ambiguity. However, the State must lay a proper foundation for the portable breath test result to be admissible.
State v. Roux, 554 S.W.3d 416 (Mo. Ct. App. S.D. 2017)

NHTSA Guidelines Must be Admitted into Evidence if Challenging Officer’s Administration of Field Sobriety Tests

A defendant appealed his DWI conviction, arguing the trial court abused its discretion in admitting testimony regarding a HGN test, and that the officer failed to follow the NHTSA while administering the test. Finding a lack of merit in this argument, the court explained that “because the NHTSA guidelines were not admitted in evidence, there is no evidentiary basis for defendant’s argument”. Because defense counsel did not admit the manual into evidence at the trial court, he failed to preserve the record for appeal and there was no evidence which the court could base a finding for the defendant on. In other words, if you are going to argue the field sobriety tests were improperly administered and should be suppressed, you better enter the NHTSA manual into evidence and be prepared to skillfully cross-examine the arresting officer.
State v. Tice, 550 S.W.3d 558 (Mo. Ct. App. S.D. 2018)



The Takeaway

Despite a grim outlook, it is not impossible to beat a DWI charge. A skilled attorney may be able to find error on the part of police which may result in evidence being suppressed, or even the case being thrown out in its entirety. Even if neither of these results are possible, an a criminal defense attorney may be able to make a case for diversion or suspended imposition of sentence if the prosecution is convinced there is a risk of going to trial. A DUI is not the end of the world, but it can have immediate and lasting consequences and be a giant hassle if you do not address it properly and keep the court satisfied. If you have been arrested for a Kansas City DUI or DWI, it is in your best interests to act quickly and secure competent legal representation. For a free consultation from an affordable DUI defense attorney, contact The Law Offices of Benjamin Arnold by phone at (913) 777-HELP, by email at ben@kcdui.com, or by visiting kcdui.com for more information.