What are Standardized Field Sobriety Tests?

What are Standardized Field Sobriety Tests?

If you are stopped by police on suspicion of operating a vehicle under the influence, you will likely be asked to perform what law enforcement call “standardized field sobriety tests.” What are these tests, where do they come from and what do they show?

Origin of the Standardized Field Sobriety Tests

Law enforcement around the country use a series of three field sobriety tests, the Horizontal Gaze Nystagmus, Walk and Turn, and One-Leg Stand tests. These three tests are used as a result of a study done by the National Highway and Traffic Safety association, or NHTSA, in 1977. The 1977 study found these three tests to be the most useful out of 10 tests studied in helping an officer determine whether a driver had a blood alcohol content of 0.1% or greater.

What are the Tests?

In the Horizontal Gaze Nystagmus Test, the officer directs the subject to follow a stimulus (usually a pen or the tip of a finger) as it passes back and forth in front of the subject’s face, to look for Nystagmus, an involuntary jerking of the eyes. Alcohol can cause nystagmus, because it disrupts the coordination of the eye muscles which need to work together to create smooth eye movement. However, there are many other causes of nystagmus, not related to alcohol, which this test cannot differentiate among.

In the Walk and Turn Test, the officer instructs the subject to stand with one foot in front of the other, heel to toe, and then walk nine steps, touching heel to toe every step, turn by keeping one leg planted and taking a series of small steps with the other leg, and then walk another nine steps back, again touching heel to toe with every step.

The One-Leg Stand test requires the subject to balance on one leg, while counting out loud. Both this test and the walk and turn are meant to test for balance as well as ability to divide attention by performing a task while listening to instructions.

Like the Horizontal Gaze Nystagmus, people may perform the walk and turn and one-leg stand tests poorly for reasons that are not related to alcohol. People who are elderly, overweight, or have back or leg injuries may be unable to complete these tests even while sober.

What Do Standardized Field Sobriety Tests Show?

As I mentioned above, studies of field sobriety tests focused on police officers’ ability to accurately predict blood alcohol content using the tests. The studies did not look at using the tests to determine driving impairment. Blood alcohol content and impairment are two legally distinct concepts, since people with different BACs may exhibit different levels of impairment due to differing tolerances for alcohol (more on this important legal distinction in another post, hopefully.) In short, the field sobriety tests are designed to show a probability that the subject is at or above .1% blood alcohol content.

If you are charged with operating a vehicle under the influence, a dui attorney can help challenge these tests, both by fighting against admission of the tests at trial, and by helping a jury to see the shortcomings of the tests. This brief post covers only a few of the many reasons that field sobriety tests are not always reliable. I hope to cover more issues with these tests soon.


“That Lady is Drunk!” – Ohio Supreme Court Addresses Reasonable Suspicion in State v. Tidwell

In State v. Tidwell, the Ohio Supreme Court issued an opinion on when a police officer may stop a vehicle on suspicion of drunk driving.

The police officer in this case was completing an accident report for an unrelated matter in a gas station parking lot in Warren County, Ohio, when he heard an unidentified man in the gas station doorway shout “Hey, you need to stop that vehicle. That lady is drunk,” and point towards black SUV that was backing out of a parking space.

According to the officer, the black SUV was moving at an “unusually slow speed” and the driver had a “blank expression” on her face, which he testified is a sign of impairment. The officer stopped the car. After speaking with the driver, Tidwell, for about five minutes, The officer asked Tidwell to perform field sobriety tests, which she did. After the tests, the officer arrested Tidwell for operating a vehicle under the influence.   

The trial court granted a defense motion to suppress, finding that the officer did not have the reasonable suspicion required under the Fourth Amendment to justify stopping Tidwell’s car. The Court of Appeals affirmed. The Ohio Supreme Court accepted jurisdiction, and reversed, holding that the stop was justified under the Fourth Amendment.

In reaching this decision, the Court held that the unidentified informant, the man who told the officer “that lady is drunk,” was sufficiently reliable under the circumstances.

The Court relied on two U.S. Supreme Court cases dealing with the reliability of informants: Florida v. J.S., and Navarette v. California.

In the J.S. case, police “received an anonymous telephone call providing a bare-bones tip that a young black man standing at a particular bus stop and wearing a plaid shirt was carrying a gun.” The anonymous tipster did not explain how they knew he had a gun or provide any other information to corroborate the tip. Police went to the bus stop in question, found an individual matching the tipster’s description, and searched his person, revealing that he did in fact have a gun. The U.S. Supreme Court held that this uncorroborated, anonymous tip lacked sufficient reliability to justify the stop and search under the Fourth Amendment, stating:

An accurate description of a subject’s readily observable location and appearance is of course reliable in this limited sense: It will help the police correctly identify the person whom the tipster means to accuse. Such a tip, however, does not show that the tipster has knowledge of concealed criminal activity. The reasonable suspicion here at issue requires that a tip be reliable in its assertion of illegality, not just in its tendency to identify a determinate person.

By contrast, in Navarette, a 911 caller “reported that a silver pickup truck traveling south at a particular mile marker had run the caller off the roadway.” The caller gave the suspect truck’s license number. Police pulled the truck over shortly thereafter. They smelled marijuana and searched the truck, discovering 30 pounds of marijuana in the truck bed. Here, the U.S. Supreme Court held that the tip, though anonymous, was sufficiently reliable under the Fourth Amendment to justify the stop. The Court found that the report of dangerous driving was made immediately after the dangerous driving occurred, making it similar to a “present-sense impression,” or “excited utterance,” two well-established exceptions to the evidentiary rule against hearsay.

The Ohio Supreme Court faced the challenge of deciding how to categorize the informant in this case. As the court noted, informants generally fall into one of three categories: (1) anonymous informant, (2) known informant (someone from the criminal world who has provided previous reliable tips), and (3) identified citizen informant.

 At oral argument, the State argued that the tipster in this case was not anonymous, because he spoke to the police officer in person, rather than by 911 call like the tipsters in both J.L. and Navarette. Unlike anonymous sources, tips from identified citizens informants are generally considered reliable. The Defense countered this argument, stating that a direct line of sight on a police officer does not transform an anonymous source into an identified citizen informant. The Court held that the informant did not fit either category, stating, “He resembled an identified citizen informant in some respects by having initiated face-to-face communication with Sergeant Illanz, but he also resembled an anonymous informant in that his identity was unknown.”

The Court held that the stop was reasonable, regardless of how they categorized the informant. The Court considered these factors important in establishing the reasonableness of the stop:

  • The informant initiated face-to-face contact with the officer,
  • The tip was about a possible crime currently in progress,
  • The tip was communicated contemporaneously with the crime’s occurrence,
  • The officer observed unusually slow driving and a blank stare,
  • The officer observed the suspect driving toward a busy road, creating a public-safety concern.

The Court concluded its summary of these factors by stating, “it was reasonable under the totality of the circumstances for him to approach the vehicle in this public area and briefly detain its driver in order to make a most basic inquiry as to whether an immediate danger to public safety existed.”

Here are my concerns with this decision as a criminal defense attorney:

  1. This decision may tempt lower courts in similar cases to avoid the difficulties of wrangling with the three categories of informants and choose the much simpler route of relying on the public safety concerns raised by the Tidwell court to justify traffic stops.
  2. This opinion states that “an informant’s tip that a drunk person is starting her car and about to drive away concerns observable and well-recognized behavior that does not necessarily require details and/or predictive information.” The Court seems to be saying that if the informant said the defendant was drunk, it must be because he saw her acting drunkenly, and his assessment that she was drunk must be reliable. This would have been akin to the U.S. Supreme Court in Florida v. J.L. concluding that if the tipster reported that the suspect had a gun, it must be because she saw a gun. Surely, guns are just as “observable” and “well-recognized” as intoxication, if not more so.
  3. The Court relied on slow driving in a parking lot and a “blank stare” as indicia of intoxication. A “blank stare,” is something so subjective, and not easily defined that any future officer could put a reference to a “blank stare” in a police report to justify a stop, and this statement would be difficult to challenge.

Still, given the very fact-specific nature of this case, it remains to be seen what impact Tidwell will have on future cases.

Read the opinion here.

Watch the oral argument here.