Chemical Testing and Roadside Tests

So, how do prosecutors convict people of drunk driving? The evidence typically falls into one of three broad categories: Driving, Field Sobriety Tests, and Chemical Tests.

     › Driving Evidence
     › Field Sobriety Tests
     › Chemical Tests

Driving Evidence

The National Highway Traffic Safety Administration has produced a guide for detecting drunk drivers at night. These are the 20 signs that officers look for when determining whether to investigate for driving under the influence. 

     › Appearing to be drunk (based upon posture, gestures, etc.)
     › Braking erratically
     › Weaving
     › Driving on other than designated roadway
     › Stopping without cause in traffic lane
     › Following too closely
     › Drifting
     › Tires on center or lane marker
     › Almost striking object or vehicle
     › Driving into opposing or crossing traffic
     › Signaling inconsistent with driving actions
     › Slow response to traffic signals
     › Stopping inappropriately (other than in a lane)
     › Straddling center of lane marker
     › Turning abruptly or illegally
     › Speed * (more than 10 miles below legal limit)
     › Accelerating or decelerating rapidly
     › Headlights off
     › Turning with wide radius
     › Swerving

NOTE - SPEEDING IS NOT ONE OF THE TOP CLUES OF D.U.I. A skilled DUI / DWI defense lawyer will know how to use this information as powerful evidence if this is a factor in your case. 

Field Sobriety Tests

These are not really tests at all:  They are physical agility exercises that are subjective in nature, and they are designed for the accused to fail.

Please note that that these tests are optional.  The officers who administer theses “tests” won’t tell you of the legal option you have to avoid these tests.  You are free to politely refuse to take any Field Sobriety Tests.

The following are some tests that law enforcement may ask you to perform.

Walk and Turn: The subject takes nine heel-to-toe steps along a line, turns, and takes nine heel-to-toe steps back. The officer will look to see if the accused can keep his or her balance and follow instructions.  Signs that the subject may not be sober include beginning early, stopping during the test, leaving space between the heel and toe, stepping off the line or losing balance while turning.

Nystagmus: The officer will position an object (such as a pen) 12 inches away from the driver’s face and move the object from side to side while watching the subject’s eyes. The officer will look for involuntary jerking or trembling of the eyeball. This jerking or trembling may be a sign that the subject has consumed an intoxicating substance.

Standing on One Leg: The accused is instructed to stand with heels together, arms at each side, and raise one leg six inches off the ground while counting out loud until the officer instructs the accused to stop. The officer will look for signs that the subject may not be sober such as raising of the arms, swaying, hopping, putting a foot down, an inability to stand still, body tremors, muscle tension and statements made by the accused during the test.

The Rhomberg Balance Test:

The accused assumes a position of attention, closes his or her eyes, tilts his or her head back and estimates 30 seconds. The officer is looking for an inability to stand still, body or eyelid tremors, opening eyes to maintain balance, swaying, muscle tension or statements made by the accused. The officer is also testing the suspect’s internal clock, which will usually be slow in the case of alcohol or depressants or fast in the case of stimulants.

Finger to Nose: This test requires the suspect to place his or her feet together while standing straight with eyes closed, and bring the index finger to the nose as ordered by the officer. The officer is looking for body sway, body tremors, eyelid tremors, muscle tension, or any statements made by the accused to support a finding of intoxication.

Other Field Sobriety Tests Include:

     › finger tapping
     › hand clapping
     › counting backwards
     › reciting the alphabet

These are tests that are supposedly designed to check “divided attention,” a critical skill in operating a motor vehicle. However, there are many people who, for many reasons, cannot perform these tests to the officer’s satisfaction, and pay the price with a DUI arrest.

Preliminary Alcohol Screening Test:

One of the most dangerous Field Sobriety Tests is the Preliminary Alcohol Screening test, also called the PAS test. This is a portable breath test to determine the presence of alcohol. The officer is supposed to advise the suspect that the test is voluntary.

The most important thing to know about the Field Sobriety Tests is that a skilled defense lawyer will know how to handle them in court.

Chemical Tests

Once a person is placed under arrest for driving under the influence of alcohol or drugs, he or she is to be told about a choice of mandatory chemical tests. Many states have “implied consent” laws that indicate that the accused has a choice of taking a blood or breath test if the arrest is alcohol related, or taking a blood or urine test if the arrest is drug related. There is no right to take a urine test for alcohol related D.U.I., unless it is suspected that the driver has a combination of alcohol and drugs in their system. You have no right to consult with a lawyer prior to taking the test.

Where the sample is blood or urine, your defense lawyer can and should get the sample tested by an independent laboratory.

If you refuse to take a blood, breath or urine test, this refusal can be used as evidence that you were conscious of your guilt. Unfortunately, evidence of your refusal can be used by the courts and the DMV to punish you.  The D.M.V. will use the information to suspend or revoke your driver’s license and the refusal can also be used to enhance the punishment in the event of a conviction.

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