Federal Studies Prove Field Sobriety Tests Are Unreliable

Police in Delaware and elsewhere will make the allegation that the field sobriety tests they administer at roadside have been approved and even certified by the federal government.   This is little more than an attempt by the law enforcement community to bolster some very debatable data.  Few police officers, if any, are familiar with the details of this ambitious claim.  Here are just a few of the things a top DUI lawyer, and any person facing drunk driving charges, should know.

What the Police Don't Want You to Know About Field Sobriety Tests

Over the past two and a half decades the National Highway Transportation Safety Administration (NHTSA) has funded several studies to examine the effectiveness of field sobriety tests in predicting a person's level of intoxication and driving impairment (e.g., Anderson, Schweitz, & Snyder, 1983; Burns & Moskowitz, 1977; Tharp, Burns, & Moskowitz, 1981).

In a 1977 report, Burns and Moskowitz examined a number of different tests commonly used by officers.  Based on the results from a laboratory study only, they recommended three tests, the Horizontal Gaze Nystagmus (HGN) test, the walk the line test, and the one leg stand test for further research.

The HGN measures the eye's angle of gaze at the onset of jerking movements which can be influenced by alcohol consumption as well as other physiological factors.  The other two tests require dividing attention among mental and physical tasks.  Surprisingly, the results of NHTSA's own studies showed that the number of false alarms or false arrest decisions were shockingly high.

In the 1977 NHTSA study for instance, 47 percent of subjects who would have been arrested based on test performance actually had a blood alcohol concentration (BAC) lower than .10 percent, the decision level used by the officers at that time.   In the 1981 study by Tharp, the error rate improved somewhat, but it was still quite high.  Thirty two percent of participants judged by police to have BACs greater than .10 actually had BACs lower than .10.

YES, I have actually read the federal NHTSA studies!   Police officers, DUI prosecutors, and other attorneys do not read these studies.

Indeed, I have extensively cross-examined under oath the leading proponent of these so called federally certified tests, Marcelino Burns, and found that the tests have never, evidently been accepted as being "scientific" by any refereed scientific journal.  This is a very disturbing finding, because the tests are promoted as having success rates quite high by the law enforcement community.

The federal tests provide no adequate norms to differentiate between different age groups, or between individuals with different weights, or for individuals who are grossly overweight. Indeed, I am aware of no study that these low police scores would be even lower, as one would suppose, if the officers had been asked to make their judgments at roadside, as opposed to being in a laboratory setting.

If you were arrested for DUI based on field sobriety test results, please call my office in Wilmington at 302-622-9500 today for a free consultation.  I will tell you the truth regarding false assumptions about DUI and sobriety tests. I will fight for you.

Kevin P. O'Neill, Attorney at Law • Wilmington, Delaware • Contact Me