Monday, April 22, 2024

DUI News Blog

The Latest DUI News and Information From DUI Defense Attorneys Across the Country

The Field Sobriety “Eye Test”: Science or Fraud?

The critical part of any pre-arrest drunk driving investigation is the administration of the “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 (walk-and-turn, finger-to-nose, one-leg-stand, 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.

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)“.)  More importantly, the scientific validity of the test is doubtful.  As a scientific study, reported in Booker, 144(3) Science and Justice 133-139, has concluded:

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 [5]. 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 whileintoxicated (DWI) [6]. 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.

If you need to consult with a DUI lawyer in Southern California, call The Law Offices of Lawrence Taylor at 888-777-3449.  With offices in Los Angeles, Orange, Riverside and North San Diego counties, the firm has limited its practice to DUI defense exclusively since 1979.

Tagged with

Lawrence Taylor

Lawrence Taylor

Lawrence Taylor is one of the most respected DUI defense attorneys in the country. With over 43 years experience in DUI defense, he has lectured to attorneys at over 200 seminars in 41 states. An original founder and former Dean of the National College for DUI Defense, Mr. Taylor's book "Drunk Driving Defense" has been the best-selling textbook on the subject for 31 years and is now in its 7th edition. He is today one of only 5 DUI attorneys in California who is Board-certified as a DUI defense specialist. A former Marine and graduate of the University of California at Berkeley (1966) and the UCLA School of Law (1969), Lawrence Eric Taylor served as deputy public defender and deputy district attorney in Los Angeles before entering private practice. He was the trial judge's legal advisor in People vs Charles Manson, was Supreme Court counsel in the Onion Field murder case and was retained by the Attorney General of Montana as an independent Special Prosecutor to conduct a one-year grand jury probe of governmental corruption. Turning to teaching, Mr. Taylor served on the faculty of Gonzaga University School of Law, where he was voted Professor of the Year, was invited to be Visiting Professor at Pepperdine University Law School, and was finally appointed Fulbright Professor of Law at Osaka University in Japan. Mr. Taylor continues to limit the practice of his 5-attorney Southern California law firm to DUI defense exclusively. With offices in Long Beach, Irvine, Beverly Hills, Pasadena, Riverside and Carlsbad, Mr. Taylor and his firm of DUI defense attorneys may be reached through their website at or by telephone at (800) 777-3349.

4 Responses

  1. I think that there seems to be far to much observatory discretion left up to police to raise a reasonable suspicion as to whether or not someone is intoxicated by alcohol or drugs. In Australia they use road side handheld breath testing machines. If a person fails that test then they must submit to a more accurate test back at the police station. Scientific machines are used by police so that there is very little room to argue for a not guilty verdict when the matter goes before the courts.

    1. I agree with you that too much discretion and subjective criteria are granted the police. However, in my experience breath testing devices are unreliable and very often inaccurate — the handheld units in the field particularly, but the larger machines at police stations as well.

      1. I would suggest that the HGN performed by police officers (even in an abbreviated or possibly inaccurate way) should only be considered qualified reasonable suspicion/and further probable cause to convince the performing police officer that the subject might very well be operating a motor vehicle under the influence of some substance or other impairment. If the subject fails the HGN test in the field, he/she should be required to provide a blood sample that can accurately determine the quantity of outside substance within the blood that could impair the driver’s ability to perform behind the wheel. Too many states will not recover blood without the subject’s permission. This is the wide open door that gets the DUI subject off of the hook. It happens too often that a subject is IN FACT operating while under the influence and a small (even almost impossible to find) technical point in the element of the law is either missed, hidden intentionally or some smart attorney manages identify and employ some other technicality and the DUI subject gets off. This is not correct. IF you have had too much to drink, it needs to be reported that way and a DUI conviction needs to be the result of a 100 percent blood toxicology report. Period !!!!! No questions, no dispute, no trickery. Just use the facts. My opinion as a retired law enforcement officer. Thank you.

Leave a Reply

Your email address will not be published. Required fields are marked *