Category Archives: Field Sobriety Tests
Roadside field sobriety tests (“FSTs”) are commonly used by police officers in DUI investigations to determine whether a driver is under the influence of alcohol. Typically, they consist of a battery of 3-5 excercises, such as heel-to-toe, one-leg stand, “nystagmus” (“follow the pencil with your eyes”), finger-to-nose, alphabet recitation, “Rohmberg” (eyes-closed, modified position-of-attention), etc. The officer will subjectively decide whether the individual “failed”.
These DUI tests have an aura of scientific credibility to juries. Unfortunately, however, they have no real basis in science and are almost useless in a drunk driving case.
First, as any traffic officer or DUI attorney knows, the decision to arrest is made at the driver’s window; the FSTs given supposedly to determine probable cause to arrest are actually for the purpose of providing “evidence” to support the officer’s opinion of intoxication.
Second, since the officer has already made up his mind, his subjective decision as to whether a person passed or failed field sobriety tests is suspect: as with any human, he will “see” what he expects to see.
Third, the conditions under which the field sboriety tests are taken almost guarantee failure: usually late at night, possibly cold, along a graveled or sloped roadside, with bright headlights from passing cars (setting up wind waves), the officer’s flashlight and patrol car’s strobe and headlights providing the lighting — and given to a person who is nervous, frightened and completely unfamiliar with the tests.
Fourth, field sobriety tests are irrelevant and, in fact, designed for failure. What scientific basis exists to validate FSTs in a DUI investigation? Only a “study” by a private business firm, the “Southern California Research Institute”, with a grant from the federal government to find a “standardized” battery of usable DUI tests.
To earn their money, SCRI came up with three tests which, they said, were not foolproof but were much better than all of the other FSTs that were being used. These three tests were heel-to-toe, one-leg-stand and nystagmus. Yet after some study even this company concluded that, using the three standardized tests, 47 percent of the subjects tested would have been arrested for DUI — even though they were under the then-.10% limit. Burns and Moskowitz, Psychophysical Tests for DWI Arrest: Final Report, DOT-HS-802-424, NHTSA, 1977.
Unhappy with this, the federal government sent the company back to the drawing board and, in 1981 the firm came up with some better figures: only 32 percent of those who “failed” the tests were actually innocent. (Tharp, Burns and Moskowitz, Development and Field Sobriety Test of Psychophysical Tests for DWI Arrests: Final Report, DOT-HS-805-864, NHTSA, 1981.) Thus, SCRI was paid to put their stamp of approval on a set of field sobriety tests.
But what has been the reaction of the (non-profit) scientific community? In 1991, Dr. Spurgeon Cole of Clemson University conducted a study on the accuracy of FSTs. His staff videotaped individuals performing six common field sobriety tests, then showed the tapes to 14 police officers and asked them to decide whether the suspects had “had too much to drink and drive”. Unknown to the officers, the blood-alcohol concentration of each of the 21 DUI subjects was .00% — stone sober.
The results: the officers gave their opinion that 46% of these innocent people were too drunk to drive! In other words, the field sobriety tests were hardly more accurate at detecting intoxication than flipping a coin. Cole and Nowaczyk, “Field Sobriety Tests: Are they Designed for Failure?”, 79 Perceptual and Motor Skills Journal 99 (1994).
The purpose of "field sobriety tests" (FSTs) is, of course, to determine if a driver is under the influence of alcohol. Rather than let the officer arrest anyone he wants, the tests supposedly provide objective evidence of impairment from alcohol.
The usual DUI investigation includes the administration of 3 FSTs to the driver. Commonly, this consists of the 3 "standardized" FSTs (SFSTs) recommended by the National Highway Traffic Safety Administration: walk-and-turn, one-leg-stand, and horizontal gaze nystagmus (the "eye test"). If some cops aren’t happy with the results, they may administer one or two more tests, hoping that the suspect will finally fail one of them.
And then again, some cops just ignore the evidence…
Tennessee: Improper to Arrest Someone for Passing DUI Test
Knoxville, TN. Sept. 5 — A Tennessee motorist who passed six roadside sobriety tests should not have been arrested for driving under the influence of alcohol (DUI), the state Court of Criminal Appeals ruled Friday. The three-judge panel rejected the attempt by prosecutors to overturn a trial court’s finding that David D. Bell should not have been taken into custody on January 12, 2010 after he displayed "excellent" mental acuity after being pulled over by a county sheriff’s deputy.
Bell had made a wrong turn in a construction area, briefly driving on the wrong side of the road — a mistake that a number of other confused drivers had made that day. Sevierville Police Officer Timothy Russell, who had extensive DUI training, arrived on the scene to take over from the deputy. Russell asked Bell to perform a four-finger count; say the alphabet from the letter G to S; identify the year of his fifth, sixth or seventh birthday; perform a one-legged stand while counting to thirty; and do a nine-step walk-and-turn. On the stand, Officer Russell testified that his mental performance was excellent, but that Bell "did not plant and turn as I had instructed him to." So Russell placed Bell under arrest.
Officer Russell admitted he did not follow proper procedure by turning off his flashing blue lights, which is a known source of distraction for the plant-and-turn test. After reviewing dashcam video from that night, the trial judge rejected Officer Russell’s conclusion.
"I honestly think that he did pretty dog-gone good on the field sobriety tests, better than most I’ve seen," Sevier County Circuit Court Judge Rex Henry Ogle observed. "I couldn’t pass them as well as he did."
Judge Ogle found the initial traffic stop legitimate but granted a suppression motion because the arrest went too far. The three-judge appellate panel also reviewed the videotape and sided with the trial judge. The appeals court found ample reason to suspect Bell might have been intoxicated, but the probable cause evaporated after testing.
"We interpret the slightly more colorful comments made by the trial court in its ruling from the bench on the defendant’s suppression motion as a finding, as a factual matter, that the defendant passed all of the field sobriety tests that he was given," Judge John Everett Williams wrote for the three-judge panel. "The state is not required to perform field sobriety tests on an individual prior to arresting him or her for driving under the influence. However, if the state chooses to administer such tests, it may not simply disregard the results if the individual involved performs them successfully. Had the defendant failed any of the field sobriety tests, we have no doubt that the state would have argued that the defendant’s failure provided strong evidence in support of probable cause. We believe that the defendant’s consistent success on a battery of such tests is likewise compelling evidence — in the other direction."
To paraphrase the great Humphrey Bogart film, Treasure of the Sierra Madre…"FSTs? FSTs! I don’t need no stinkin’ FSTs!"
The critical part of any drunk driving investigation is the administration of "field sobriety tests" (FSTs). These usually consist of a battery of excercises involving balance, coordination and mental agility — and are difficult to perform for even a sober person under ideal conditions (see "Field Sobriety Tests: Designed for Failure?"). Although there are many different tests (finger-to-nose, alphabet, etc.), an increasing number of law enforcement agencies are requiring their officers to use only the federally-recommended battery of three "standardized" FSTs. The most recently developed of these three is horizontal gaze nystagmus (HGN), commonly known as the "eye test". It is particularly effective in trial not because of its accuracy, but rather because it appears to jurors as scientific in nature.
As I have indicated in previous posts, however, HGN as a test for intoxication is fundamentally flawed and rarely understood or properly administered by police officers. See "Nystagmus: The Eye Test", "Nystagmus: The Eye Test (Part 2)", and "Nystagmus: The Eye Test (Part 3)".
A scientific study (144(3) Science and Justice 133-139) has investigated the scientific validity of the nystagmus test:
The Horizontal Gaze Nystagmus (HGN) test was conceived, developed and promulgated as a simple procedure for the determination of the blood alcohol concentration of drivers suspected of driving while intoxicated (DWI). Bypassing the usual scientific review process and touted through the good offices of the federal agency responsible for traffic safety, it was rushed into use as a law enforcement procedure, and was soon adopted and protected from scientific criticism by courts throughout the United States. In fact, research findings, training manuals and other relevant documents were often held as secrets by the state. Still, the protective certification of its practitioners and the immunity afforded by judicial notice failed to silence all the critics of this deeply flawed procedure….
In 1998 the integrity of the statistical evaluation of the original research upon which the validity of the tests rested was unfavorably reviewed . In 2001 new research indicated that the Horizontal Gaze Nystagmus (HGN), the cornerstone of the test battery was fundamentally flawed and that the HGN test was improperly conducted by more than 95% of the police officers who used it to examine drivers suspected of driving while intoxicated (DWI) . This summary critique demonstrates that it is scientifically meretricious and that the United States Department of Transportation indulged in deliberate fraud in order to mislead the law enforcement and legal communities into believing the test was scientifically meritorious and overvaluing its worth in the context of criminal evidence….
Deliberate fraud. Pretty strong language for a scientific journal. After reviewing the flawed and deceptive justifications for using nystagmus in DUI investigations, the researchers concluded that the test was essentially without scientific validity.
The state’s argument for the field sobriety tests does not rest on proof of merit, but upon qui tacet consentit reasoning that those tests have been so widely accepted they must have been subjected to some kind of review prior to adoption in the many jurisdictions where they are used, that somewhere along the way someone would have spotted the flaws and shortcomings. Considering that the student manual was originally considered to be a confidential state document and was only obtained through an Open Records Act request, silence from the scientific community cannot be considered an endorsement of the program.
Want to know where we’re going with MADD’s hysterical "war on drunk driving"?
DUI Deputies May Be Posted in Drive-Thrus
Is this latest Big Brother craziness really going to be effective in reducing the level of alcohol in drivers — or just their level of cholesterol?
(Thanks to Andre)
There are many so-called “field sobriety tests” used by officers supposedly to determine a DUI suspect’s sobriety. And, as I’ve posted in the past (Field Sobriety Tests: Designed for Failure?), these tests are highly unreliable and largely used to justify the officer’s suspicions. Of the many “tests” used today, only three have been approved by the National Highway Traffic Safety Administration: walk-and-turn, one-leg-stand and horizontal gaze nystagmus (HGN, or the “eye test”). Collectively, they are referred to as the Standardized Field Sobriety Tests (SFSTs). Although they are in reality no more valid at determining intoxication than the other tests, their adoption by the federal government has given them an aura of credibility. The most insidious of these three tests is the nystagmus test – because of its seemingly scientific nature. Yet, as I’ve previously posted, HGN is unquestionably the least reliable of the FSTs. (DUI “Eye Test” a Fraud?).
A growing number of states are now questioning the validity of such tests, as shown in the following recent news story:
DUI ‘Eye Test’ Under Fire by Supreme Court
State justices join critics, but test has its supporters, too
When it comes to a suspected DUI, the eyes don’t lie.
That’s the principle behind horizontal gaze nystagmus testing, which has long been considered the most reliable way, short of a blood or breath test, for a police officer to determine whether a driver has been drinking.
However, the Illinois Supreme Court has dealt a potentially serious blow to HGN testing with a recent decision stating that such tests are not presumed scientifically valid in Illinois…
“Based on my training and experience, the test is very reliable,” (Dixon Police Department Sgt. Dan) Langloss said. “Yes, the test does have its flaws and drawbacks, but it is only one factor that we look at during a DUI stop. You have to look at the totality of circumstances.”
Many critics across the country, including defense attorneys, argue it is difficult to determine the accuracy of HGN testing and that there are many factors that can cause the eyes to visibly jerk aside from alcohol consumption.
“There are over 25 different types of nystagmus,” said Bob Thompson, Lee County public defender. “Officers are not taught about the other types, which they should know about. Fear, anxiety and viral infections, to name a few, can all have an affect on the eyes.”
Thompson added there are other factors that can affect the results of an HGN test, such as exposure to the lights on the squad car and the difficulty that an officer may have when determining an exact 45-degree angle when conducting the test.
“Officers are not trained in scientific methods or medicine,” Thompson said. “During cross examination, it’s difficult to ask them to draw us a 45-degree angle or test their geometry skills. That’s where we’re starting to see the trial courts become more strict when admitting the test.”
The court ruling came in the wake of a Peoria County case involving Joanne McKown, who was convicted of multiple counts of DUI and reckless driving after she hit three motorcyclists in June 2002. Having suffered a broken toe, she could not perform other sobriety tests, such as standing on one leg or walking heel-to-toe. A sheriff’s deputy who administered an HGN test 90 minutes after the accident said she failed. After McKown refused to give blood voluntarily, police got a search warrant and drew blood 6 1/2 hours after the accident. Tests showed no alcohol in her bloodstream.
Writing that “HGN testing appears to have as many critics as it does champions,” the state Supreme Court sent the Peoria case back to the trial court in September.
(Thanks to John Kruzelock.)