The Law Offices of Lawrence Taylor, Inc.

The Evidence in Your San Diego DUI Case

While all San Diego DUI cases are inherently different, the evidence collected can subsequently be cataloged into 6 general categories.

Driving Symptoms:

Driving symptoms are usually the first signal a police officer receives that a person may be driving while intoxicated (with the exclusion of an accident). The National Highway Traffic Safety Administration recognizes 24 different driving patterns that can indicate a possible drunk driver. Some of the more common symptoms of an intoxicated driver include, but are not limited to, making turns at a wide radius, weaving through traffic, straddling lanes, or braking erratically. One should make note that speeding is not one of these factors as it generally requires keener reflexes, sharper coordination, and better judgment skills.

Personal Appearance and Behavior:

As the officer approaches the vehicle, he begins to gather the second type of evidence used against a DWI suspect; his analysis of the suspect's physical and mental state. This procedure is one that is not in the favor of the suspect, as the officer will start to gather evidence against the suspect even before his interrogation begins. Any evidence he gathers from the suspect (i.e. speech patterns, physical characteristics, and overall appearance and disposition) may be used against the individual in court as admissible evidence under the pretense that it is included as part of the officer's initial assessment. The physical characteristics of a suspect such as, bloodshot eyes, inability to follow directions, difficulty in retrieving identification, slurred speech, the scent of alcohol on a person's breath, and the inability of the person to stand without assistance are frequent indications officers encounter while dealing with a DUI suspect. These distinctive cues are so frequent, in fact, that many officers will include such evidence in their reports even if the suspect did not display said characteristics.

Field Sobriety Tests:

The third category of evidence comes in the form of Field Sobriety Tests (FSTs). There are twelve commonly used Field Sobriety Tests (FSTs) that include tests such as:

• Fingers-to-thumb
• Finger-to-nose
• One-leg-stand
• Walk-and-turn
• Head/Hand pat test
• Finger counting
• Counting or reciting the alphabet in reverse
• Horizontal gaze nystagmus (following a small object back and forth with your eyes)
• Modified position of attention test (also known as the Rhomberg test)

The first thing one should know about FSTs is that as long as the suspect is over the age of 21, these tests are optional and not required by any form of legislation. That being said, most police officers will not inform a potential suspect of this right as it hinders the gathering of potential criminal evidence against said suspect. Another factor that one should take into account is that federal research has concluded that only three of these twelve tests are proven to show conclusive evidence that a DUI suspect is in fact driving while intoxicated. These three tests are the horizontal gaze nystagmus, the one-leg-stand, and the walk-and-turn. The studies concluded that the other nine frequently used tests failed to prove a suspect impaired as they could not be completed by a significant percentage of non-impaired individuals. In recognition of this, the set of three standardized field sobriety tests is slowly being adopted all over the country as standard operating procedure, though many officers still use whatever tests they are familiar with.

PAS Tests:

The fourth type of evidence used in a DUI case is typically a breath-alcohol test taken at the scene using a portable breathalyzer. This device is known as PAS (Preliminary Alcohol Screening) unit, or more recently as an EPAS (Evidential Portable Alcohol System). The small, hand held machines are intended to give the officer a generalized read out of the suspects blood-alcohol levels and assist the officer in making a judgment of the suspect after the other FSTs are completed. It should be said that these devices are frequently inaccurate in their results, as they fail to take many proven scientific factors into their equation (the suspect's gender for example). Despite their known flaws, the results of said tests are often admitted as key evidence in the case against you. It should also be stressed that submission to a breath test, like the FSTs, are not required by law as long as the suspect is over the age of 21.

Chemical Tests:

The term Chemical Test encompasses both blood and breath-alcohol tests. These two tests are the only admissible tests currently used in California. Urine analysis, while previously accepted, has been discontinued as a means of testing, (except in the rare case that neither of the other tests are able to be accurately preformed) as of the year 2000. As it is, there are a wide variety of different testing apparatuses in use by police agencies around the country. The one common factor that all of these various machines possess is the ability to provide less than accurate information about a suspect's blood-alcohol levels.

As previously stated above, the major flaw in these devices is their inability to provide a comprehensive analysis of blood-alcohol levels on an individually unique level. The machines simply generalize all individuals to the same standards, failing to take scientifically proven factors such as a person's weight and height, individual metabolism, and their gender into account. One study even found that if a person belches or burps, that the breathalyzer can give a false reading of that person's BAC up to 15 minutes later. Other investigations found that even radio frequency interference (RFI) has been known to have possible negative effects on test results. Finally one of the biggest aspects that cause failure among PAS units is the fact that the machine is not intended to specifically detect alcohol in a person's blood system. The machine is designed to detect the presence of methyl compounds found in the molecular structure of alcohol. Seeing as methyl groups are found in thousands of different compounds, (over 100 of which can be found naturally in human breath) the margin of error of these machines dramatically increases the chance of false positives.

Blood analysis, while proving to be generally more accurate, still has a margin of error within its results. Such errors include possible mishandling/mislabeling causing a mix up in the lab results, improper sterilization/sanitation issues, fermentation of the blood sample in the lab, or even coagulation of the blood.

Incriminating Statements:

The final category of evidence is the statements made by the individual prior to an arrest. As stated prior, the officer analyzing the suspect begins to take mental notes about a suspect as soon as they ask you for your identification. This is the beginning of their interrogation. Answers you give to their questions are viable evidence in their case against you and are admissible in court even without the officer having to issue a Miranda warning. This is because the answers you give are deemed to be evidence gathered by the officer during initial investigation of the situation. The law states that a Miranda warning does not come into effect until after an actual arrest has been made. This is often why the officer will ask incriminating questions of a suspect, such as, Have you had anything to drink this evening? It should also be noted that statements admitted by the suspect without interrogation, as well as choosing not to submit to a breath/blood alcohol test, can be submitted as admission of guilt in court.