D.U.I. Defense is an artform. It involves a combination of legal knowledge, scientific knowledge, case specific research, and experience. The law seems to change annually, and the science develops continually. Law enforcement screening tools were recently updated, although the science behind the changes remains questionable.
The National Highway Traffic Safety Administration (NHTSA) develops the national Standardized Field Sobriety tests for D.U.I. / D.W.I. detection. Law enforcement officers ask motorists to perform these tests as part of their D.U.I. / D.W.I. investigation. In March 2013, NHTSA updated the manual, making it even more "law enforcement friendly." Nevertheless, the manual offers help to the well trained D.U.I. / D.W.I. practitioner.
The obvious first step is to obtain a copy of the manual and learn what it contains. At 353 pages, it takes time to read, but it can be the difference between conviction and acquittal for the client.
The manual covers three general phases of investigation: (1) Vehicle in Motion, (2) Personal Contact, and (3) Pre-Arrest Screening. Interestingly, the majority of the manual covers activities before SFST's are administered. The new manual deals extensively with probable cause for investigation, which can yield pure gold on cross-examination of the arresting officer. "So the actual traffic stop you performed failed to comply with national standards?"
In addition, the 2013 manual adds a test. Prior to 2013, there were three - and only three - SFST's. The Horizontal Gaze Nystagmus Test, the 9-Step Walk and Turn, and the One-Leg Stand. The 2013 manual adds Vertical Gaze Nystagmus, with indicators and testing protocols.
Reading the new manual is essential for proper DUI defense. It can be purchased from the National Association of Criminal Defense Lawyers.
As a final note, defendants facing DUI or DWI charges may want to make sure that their attorney is familiar with the new standards.