The Law Offices Of Roderick C. White

Motorists suspected of DUI / DWI are routinely asked by police officers to perform one or more field sobriety tests. These tests were developed by police agencies to assist law enforcement officers in making roadside determinations as to whether a motorist is under the influence of alcohol or drugs.

A motorist alleged to have performed poorly on these tests provides the probable cause or legal justification the officer needs to arrest. Also your performance will become part of the proof used later to convict the person at trial. Accordingly, almost EVERY knowledgeable DUI/DWI attorney will almost always strongly advise against attempting any of these tests.

The three field sobriety tests typically used in Texas are (1) the walk and turn [WAT] test, (2) the one leg stand [OLS] test, and (3) the horizontal gaze nystagmus [HGN] test (nyatagmus is the involuntary jerking present in everyone's eyes; it is alleged that alcohol exaggerates this jerking).

Despite the "junk" science that law enforcement uses to validate these tests none are very reliable. The WAT exercise, when conducted properly on a qualified subject on a dry, level surface, was found to be 68% reliable in determining intoxication. This means that 32% of the people who perform poorly on the WAT are quite likely not intoxicated. The OLS exercise, when conducted properly, on a qualified subject on a level, dry surface, after proper instructions and where correctly demonstrated and scored, is about 65% reliable. Accordingly, 35% of people who allegedly fail this test are not actually intoxicated. Likewise, the HGN evaluation, when performed correctly on proper subjects and interpreted accurately, had a 77% reliability rating. Therefore, even under the best circumstances 23% of the people who, based upon their HGN evaluation, police officers believe are intoxicated in reality are not.

If you have mistakenly subjected yourself to these tests we will challenge the subjective nature of the evaluations, the accuracy of the principles behind the tests, the accuracy of the administration of the tests, the credibility of the officer who requested and administered the tests, and challenge all circumstances connected with the evaluations. Knowledgeable criminal defense lawyers know that 98% or more of the officers administering these evaluations do them wrong, or conduct them in a manner (or on a test subject) not approved by the manual, or grade the evaluations improperly, as per the manual, or ALL OF THE ABOVE. When done incorrectly, these evaluations loose their predicted reliability. Hence, a top-notch DUI/DWI lawyer can cross-examine the arresting officer using his/her OWN training materials.