San Diego DUI Legal Guide

Field Sobriety Tests

Police Procedures and Evidence

There are five types of evidence in a DUI case:

1. Chemical evidence of alcohol present in the blood – in California, urine tests are given only where breath and blood tests are not available. Normally, however a breath test is preferred.
2. Statements that cause suspicion of intoxication – "Really, I’ve only had a few drinks."
3. Indications of drunk driving – lane straddling, false signals, swerving, etc.
4. Personal indicators – bloodshot eyes, trouble focusing, mumbled speech, etc.
5. Field sobriety tests – hand-pat, fingers-to-thumb, etc.

During the process of the police investigation and collection of this evidence, as a citizen you should be knowledgeable of the rights you are entitled to. Often, these rights are disregarded by officers:

• When breath tests are taken at the police station, the results are not kept on file. An individual has the right to request a blood test for later use by their defense attorney.
• Legally sufficient evidence must be given to account for "probable cause" to halt, hold, or arrest an individual.
• It is not required by law that an individual take a field sobriety test.  A field breath test (PAS or "preliminary alcohol sensor") is only required of drivers under the age of 21.
• The "Miranda" warning must be given when an individual is arrested:  The officer must state an individual’s constitutional rights before interrogation continues.
• An option must be given between breath and blood tests. If an individual chooses not to take either, he/she must be informed of the legal implications ("implied consent" advisement)

The 'Nystagmus' Test
Although efficient by scientific standards, the nystagmus test is completely unreliable. Also known as the "horizontal gaze nystagmus," this examination involves following a small object, such as a pencil, moving only the eyes. The main factor in the lack of reliability of the test is the officer’s skill and judgment in conducting it. To see an example, see Cross-examination - Duplicated from the book "Drunk Driving Defense, 5th edition" written by Lawrence Taylor, a Los Angeles-Orange County attorney (refer to The Best DUI Lawyers).

Officer's Manual to DUI Driving Signs
Including statistics like - A wide angled turn gives a 65% possibility that the individual driving is inebriated. – this guide provides officers 20 indicators to be wary of with drunk drivers. – Provided by the U.S. Department of Transportation.

Field Sobriety Tests
Discussion of the three tests referred to as the "standardized field sobriety tests." The three being: heel-to-toe, nystagmus tests, and one-leg-stand. Generated by the U.S. Department of Transportation.

Standards for Sobriety Roadblocks
Provided by the National Highway Traffic Safety Administration, this is a suggested checklist for the customary law enforcement procedures for DUI sobriety roadblocks.