Former Municipial Court Judge

Former Assistant District Attny.

Denton County Office 940-580-2899
Collin County Office 972-954-1947

What You May Not Know About DWI- Law Offices of Tim Powers, Denton, Texas

What You May Not Know About DWI

Tim Powers

Law Offices of Tim Powers, Denton, Texas


1. Although DWI stands for Driving While Intoxicated – Driving Isn’t Necessarily Driving

The elements of a Texas DWI require that the State prove a person was “operating” a motor vehicle in a public place while intoxicated. Driving and Operating are two different things. Whether or not one was operating a motor vehicle depends on the facts and the totality of the circumstances. But the car might possibly be off. This clip from “Everybody Loves Raymond” is illustrative of what is certainly possible.

2. Refusing a Blood or Breath Test is Not an Admission of Guilt

Texas law only provides for a presumption of the presence of a prohibited substance in your system if you refuse to take a State-Administered Blood or Breath test in a DWI case that is a piece of evidence which can be considered but it is not an admission of guilt.

3. If You Refuse the Test You Will NOT Definitely Lose Your License for 180 Days

If you refuse to take a breath or blood test, a license suspension is not automatic. If you request an Administrative License Revocation hearing within 15 days to the Texas Department of Public Safety a license hearing will be scheduled with the State Office of Administrative Hearings. Only after this hearing can a driver's license be suspended for refusing a State-Administered Test.

4. You Can Beat a Breath or Blood Test Result DWI - It is Not Always Hopeless

Because there are many opportunities for a strong defense in cases with State-administered results, we regularly beat DWI cases with blood and/or breath tests as evidence. For one, was the stop legal? Many cases can be dismissed because of illegal stops. Second, was there enough evidence - probable cause - to arrest you for DWI in the first place? Although relatively rare because the standard for probable cause is so low, we have won a number of DWI cases based on a judge finding no probable cause for a DWI arrest. Third, did the police officer correctly read you the implied consent rights (Statutory Warning)? This is the most common source of police error in DWI cases. We have had multiple DWI cases thrown out due to the Implied Consent rights or DWI testing rights not being read in the correct manner or at the correct time. Fourth, were the breath test machine or blood testing records maintained or functioning properly? This is another area of success for our firm in defeating DWI cases. Finally, there are the inherent weaknesses in the science of breath testing creating doubt for jurors. We have won breath tests as high as .143 in front of a jury simply by demonstrating that breath testing is not as reliable or accurate as the State contends. We often contrast the relative sobriety of our client on the video with the high breath test reading and simply ask, "do you trust your common sense, your eyes and ears or the government's junk science?"

5. Field Sobriety Tests Are Not Reliable Indicators of Alcohol Impairment

The three most commonly used field sobriety evaluations are the Horizontal Gaze Nystagmus Test, or eye-jerking test, the nine step walk and turn, and the 30 second one leg stand. These tests supposedly correlate specific clues with blood alcohol levels, but not "impairment" as so often testified to by police on the witness stand.

These tests were validated by NHTSA in the 1970's in a controlled environment using a cross-section of the population and found that they are reliable around 70% of the time. Other non-controlled studies have been done with higher percentages, but they have been by police and in the field after midnight, which tends to focus on a much narrower cross section of the population.

HGN is naturally present in approximately 2 % to 8 % of the population without the presence of alcohol. Medical disorders such as inner ear infections, vertigo, water in the ear and Meniere's disease can cause the eye to jerk or HGN as if alcohol had been ingested. DWI police officers tend to use more than the standardized number of passes for the HGN test and move the pen or target object back and forth several times more. They claim to be making sure they are performing the entire test, but in reality they are actually inducing eye jerking or HGN.

Most police officers can't even name the muscles of the eye they are testing during HGN. The HGN tests the lateral and medial rectus muscles as well as the cranial nerves that innervate the muscles. The 6th cranial nerve, or the abducens, is tested by the HGN procedure. These muscles are like "rubber bands" and easily fatigue and begin to spasm or "jerk" when over-stimulated. That, of course is the same HGN produced by alcohol ingestion.

The Nine Step Walk and Turn and the One Leg Stand are divided attention dexterity tests. These tests are easier to do with practice. The first time you try them they are often impossible regardless of whether you have been drinking. Just ask them about how long it took them to learn to ride their bicycles, ice skate, roller skate or perform yoga balancing moves. Many athletic activities require practice and frequent repetition in order to perform fluidly, which has no relation to alcohol consumption.

The Rhomberg test is another sobriety evaluation that is misunderstood and misapplied by police in DWI investigations. In the Rhomberg test, the subject is asked to stand with feet together, tilt the head back slightly, close the eyes, and estimate 30 seconds. The Rhomberg Test is a test for Upper Motor Neuron disease. Many older adults will fall over when performing this test without the presence of alcohol.

We encourage our juries to try these tests back in the jury room so they can see how easy they are to fail.

6. You Will Not Go to Jail for a First DWI Arrest

Although the DWI Statute describes the punishment for a first DWI as a minimum of 72 hours in jail, it also allows the judge to probate all of the jail time – including the minimum sentence. Practically speaking, sometimes first time DWI offenders may get no additional jail at sentencing.

7. The State-Administered Breath Test at the Jail or Police Station, the Intoxilyzer 5000, is Not Always Accurate and can be Beaten in Court:

The Intoxilyzer 5000 alcohol breath test machine is flawed, because it has to make assumptions. It assumes, for one, that your body temperature is normal. If you have a fever, every degree of body temperature variation from normal will cause a 7% change in the breath test result. It assumes your "partition ratio" is 1:2100. This means that for every particle of alcohol in your lungs, it assumes there are 2100 particles in your blood. Human partition ratios can vary from 1:1500 to 1:3400. It assumes that your blood alcohol level has peaked and is decreasing. It generally takes 30 minutes on an empty stomach and 2 hours on a full stomach for your blood alcohol to peak. If you blow before you peak, then your breath alcohol level can be as much as 50% higher than your blood alcohol level, because breath alcohol comes from your arterial blood system and blood alcohol level is drawn from your veins. Given the same body size, women will have a higher blood alcohol level than men after drinking the same amount of alcohol, so using blood alcohol levels as a per se determination of DWI discriminates against women. Also, the Intoxilyzer 5000 has a margin for error. It can vary as much as .02 between samples because of variations in deep lung air. It can mistake solvents such as acetone and ketones as blood alcohol on the breath. Radio frequency interference from cell phones can cause errors in breath alcohol readings. It can also mistake residual mouth alcohol from burping and belching as blood alcohol. The Intoxilyzer 5000 used in states where it is calibrated between every test automatically rather than every three months averages 80 errors per month. This is not science fiction. We have the police training manuals and owner's manuals that spell out these very flaws and we use them in court.

8. The Legal Limit of 0.08 BAC is Not Necessarily Drunk

Most people think that if you blow over 0.08 (the legal limit for BAC in Texas) that you are drunk. Not true. Most people can perform field tests quite well at the .08 level and not have slurred speech, stagger or stumble. They may simply not be drunk, although they may not be sober. Alcohol affects different people differently. Some people are not even drunk at .13 or .15 and that is why if you refuse to blow or we get the breath test thrown out of court, we can often win your case. If the State does not have breath or blood, they have to prove that you are either less safe to drive or that you are drunk, which is often hard to do because the legal limit is so low and seemly arbitrary.

9. Court Appointed Attorneys are not Free

Most jurisdictions require a defendant to reimburse the county for a court appointed attorney, but you will never have to pay one up front.

10. If Your Attorney Tells You to Plead Guilty at Arraignment, He Probably Has Not Done His Job

Most Courts don't provide attorneys with needed evidence to evaluate your case until at least after arraignment and sometimes not until 20 days before trial. Before you plea, make sure you and your lawyer has reviewed the police report, video and all evidence in the case.