Texas DWI attorney Phillip W. Goff explains how breath testing works, the Intoxilyzer 9000, your rights on refusal, and how to challenge results in court.
Breath testing for alcohol seems to be a mystery to the general public. For most people, breath testing devices are effectively magic boxes used to convict drunk drivers by showing a number above the so-called “legal limit.”
It should be no surprise people’s understanding of breath testing usually is limited to two parts: 1) a person arrested for DWI/DUI blows breath into a tube connected to a machine; and 2) the machine produces a number to quantify a breath alcohol content or concentration (expressed as BrAC, as opposed to BAC, which is for blood). Everything between #1 and #2 probably is about as clear to people as how their mobile phones and computers work, which is to say not clear at all.
This page is intended to give the public an improved understanding of breath testing associated with driving while intoxicated arrests, primarily in Texas.
If you are worried the topic will go over your head because you aren’t a math whiz or scientist, don’t worry. You won’t need to be an expert on anything. Much like my blog on understanding and challenging blood tests, this talk is intended to simplify a relatively complex topic. Whenever a seemingly complicated term is used, I’ll endeavor to make it clear in its context.
By the time you finish reading, breath testing won’t be nearly as murky to you. My hope is you will have the healthy suspicion about breath testing I think it deserves. My guess is you will not want to blow into their device after reading this.
You even may be influenced to absolutely avoid alcohol and drugs prior to driving. After all, if you reasonably suspect the evidence against you will include an inflated BrAC number, even truly being under the “limit” doesn’t protect you. Eventually, you may serve on a jury which hears breath test evidence and will think about what you learned.
Before I go further, I will address the elephant in the room only because so many people ask. The predominant question I get about breath testing has nothing to do with understanding the topic. In fact, the question is indicative of the mysteriousness and fear of something people don’t understand at all. It’s all about what to do after getting arrested for DWI. “If I’m arrested for DWI, should I blow or not?” People still ask me about this more than anything else I do, even after 30 years.
If you are asking that question, it presupposes you are planning on driving after drinking alcohol, which means you are planning on putting yourself at risk of arrest for DWI. That’s an unnecessarily risky plan. For anyone asking so they can plan what to do after getting arrested for DWI, my advice is to avoid getting arrested at all. No DWI arrest means you won’t need to go through one of the worst ordeals of your life. Simply do not drink alcohol at all before driving. Alternatively, you could ask a friend for a ride, get a rideshare or taxi, or drink where you’ll stay.
That’s not to condemn you for drinking and then driving when you are not intoxicated. The law doesn’t strictly prohibit driving after drinking alcohol, nor does intoxication occur with the slightest amount of alcohol consumption. However, you can reliably expect a cop to arrest you, should you be pulled over and have the odor of an alcoholic beverage on your breath. That is not to say they should base an arrest on so little, but they do.
Now that you’ve been advised and hopefully will avoid a future DWI arrest, I’ll address the actual question. However, I will explain, rather than simply giving a one-word answer, since I believe a simple “yes” or “no” to the question would be a disservice to you.
I have a professional preference, but there is no one correct or best answer to cover all circumstances. I am of the opinion the best idea usually is DO NOT BLOW. This opinion may not even matter, though, because you may never even get the chance to refuse a breath test, due to the fact the cop can decide not to offer you that option.
In short, I would rather the state have less evidence than more evidence. Since the state has the burden of proof in a driving while intoxicated (DWI) case, the less evidence it has, the better the chances of a “not guilty” verdict.
If given a choice, I also would prefer evidence which allows me greater opportunities to argue for reasonable doubt. Blood testing has many more steps than breath testing to question and examine, and every step is an opportunity for error. Every such error could be the basis for a “not guilty” verdict.
Blowing may be helpful in some highly limited circumstances, but not most. Breath testing devices used in Texas can usually accurately detect the mere presence or absence of alcohol, even if the number is inaccurate.
So, the primary reason I’d suggest you blow into the state’s machine is when you have had no alcohol at all to drink, but that has extremely limited application. Relatively few people arrested for DWI blow a .00.
Even if that happens, you’ll probably have to defend a charge of being under the influence of drugs. After all, the cop already opined you are intoxicated, and a .00 breath test effectively eliminates alcohol as the intoxicant. To summarize, having no breath test is almost always better than having a breath test, but refusing a breath test does not mean cops won’t get evidence against you.
If you have had absolutely no alcohol to drink, a breath test MAY be good for you. However, clients I’ve defended have never been released by cops after a .00 BrAC result. Instead, cops just assume or pretend they know you are under the influence of a drug or drugs. Their next step is almost always to get a search warrant for blood.
As a rule, I think of the breath testing program as being unreliable and skewed to be unfair. It can and certainly does convict innocent people with inaccurate and unreliable application of science to criminal evidence in real-life cases.
I think you should have a better understanding of breath testing to make sense of it, though.
General answers to flawed questions are an open invitation to being seriously wrong. One change in circumstance could lead to radically different considerations and even a completely opposite answer from the general situation. Lawyers know countless specific factors affect the answer. A critical part of our job is to consider such factors before rendering advice. Asking the right question is essential. “To blow or not to blow” definitely is not the right question because it’s incomplete.
I’ll mention four (of MANY) easily identifiable flaws in the question: 1) the arresting officer may ask for blood, not breath, and Texas law gives the officer the choice, not you; 2) refusing to blow may lead to its own criminal charge, one often much easier to prove than your DWI charge, which is applicable in some other states and under federal law, such as arrests made on Padre Island National Seashore or military bases; 3) you may be unconscious or otherwise unable to make any choice; and 4) if you refuse, your blood may be drawn against your will.
Many other examples of how flawed the question is come to mind, but I don’t want to make an exhaustive list. I just want to emphasize the answer isn’t simple and depends upon the circumstances in the case.
*THIS DISCUSSION IS NOT applicable to portable, hand-held devices used on roadside – This entire discussion is about the breath testing device whose result may be used as evidence of intoxication, NOT the roadside, handheld version.
My own observations as a DWI defense attorney reviewing evidence in many cases are Portable Breath Tests (PBTs, also known as Preliminary Alcohol Screening, or PAS devices) are extremely inaccurate and tend to skew higher than evidentiary breath test devices found in police stations and jails, as well as higher than blood results from a lab.
Rarely have I seen news published to address this observation, but a Corpus Christi, Texas, television station recently reported on such a situation. The news story on mentioned both the PBT result and a blood test result in an intoxication manslaughter case. The difference was roughly 50% higher with the PBT%. A “preliminary test” read 0.22 on a sample of breath. A blood draw from two hours later on the same person had a .15 result.
I acknowledge the importance of the difference in timing between samples. However, in the event you think the two hours caused the 50% difference of .07, you’d have to assume an alcohol elimination rate far in excess of the normal rate of .015-.020 per hour. Elimination phase is essentially when alcohol is metabolizing or excreting from the body, what most people would think of as the process of “sobering up” after being intoxicated. Two hours between the samples barely makes up half of that .07 difference, even if you make the ASSUMPTION the person was in the elimination phase the entire time.
*Breath testing is NOT necessary for prosecutions of Public Intoxication and underage drinking charges. Occasionally, it may be included with DUI (Driving Under the Influence of alcohol by someone under 21 years of age) and Minor in Consumption/Consumption of Alcohol by a Minor.
Winning or losing your DWI case understandably makes for compelling and highly personalized drama and consequences. Evidence or lack of evidence at your trial has direct relation to the verdict. Multiple laws affect the sample requested and/or obtained. This page cannot comprehensively address all the laws associated with breath testing, so this section is intended to cover the ones with the most direct applicability to most cases.
Legally, you may never get the opportunity to make a choice to take or refuse a breath test. The arresting officer legally gets to choose which type of sample you’ll be asked to give. (See Texas Transportation Code Section 724.012 (c)*). It’s also critical to understand refusal does not require an affirmative and forceful “NO!” Anything short of prompt obedience to the cop’s request is legally considered refusal.
For example, refusal includes a polite request to talk to an attorney before deciding whether to obey the cop, so your DWI arrest effectively means you don’t have a right to an attorney to assist you after your arrest to navigate whether you should cooperate with your accusers.
Also, if the cop gets a warrant for blood, your consent won’t matter at all whether a sample is obtained. A warrant allows cops to legally strap you down and have a needle forcibly jammed into your body. You might think it would be hard to get a judge to authorize such a forcible blood draw in the United States of America, Land of the Free; you would be dead wrong. This even applies to misdemeanors with no bad driving, no wreck, no fault, no injury, no death, and no breath test.
Even worse, the incredibly low burden of proof required for a warrant is probable cause that an offense has been committed.
Judges routinely grant virtually every DWI blood warrant request based solely on what the cop decides to disclose. For example, a cop can allege to the judge that he/she smelled the odor of alcohol on your breath and you failed to adequately perform a one-leg stand, yet make no mention of the fact the cop also knows both your legs were injured in a crash, rendering you unable to successfully perform the task. The judge, hearing only one cherry-picked version of the truth, routinely will authorize the cop to stick a needle in your arm.
Law enforcement agencies’ policies don’t have the same legal status as a statute like in the Transportation code, but such policies may make the cop’s decision for him/her. Some agencies have judges on standby 100% of the time to process search warrants for blood when requested by cops after refusal by an arrested person to give a sample. Ultimately, the popular question of “should I blow” doesn’t have as straightforward an answer as I’d like to give.
Also, if the cop requests any of the samples, you can certainly refuse, but there are other consequences to refusal.
One consequence could be suspension of your driver license through the Administrative License Revocation (ALR) procedure, which is part of the Transportation Code. ALR hearings are an important standalone topic and are discussed in the last FAQ at this link.
How long a suspension may last is directly tied to 1) whether you refused to give a requested sample (or provided a sample of .08 or greater); and 2) whether you have a prior “alcohol related contact,” usually meaning a DWI arrest, from the past 10 years.
Refusal has a range of suspension between 6 and 24 months. Test “failure,” defined as providing a sample of .08 or greater, has a suspension range of 90-365 days. In other words, ALR suspensions are doubled for refusal versus test “failures.” There is one exception.
Only if you are found “not guilty” after a criminal trial will the ALR suspension legally be negated. That is the only intersection of the ALR and DWI cases. The two cases don’t go at the same speed to resolution, since they are in different courts with different rules. The result is you could lose the ALR long before you get to trial on the DWI criminal case.
While you wait for the criminal trial, you may suffer through the suspension. If your “not guilty” verdict comes after you’ve served the suspension of your driver license, the effect is you were punished for a crime the state couldn’t prove you committed. That’s Texas “justice.” Thank your Legislature for this form of “justice” under its laws.
It may be difficult to believe, but even a dismissal of your criminal case has no effect on an ALR. That’s right. Even if a prosecutor in your criminal case decides the evidence in your case is so weak it’s not worth filing the DWI case, or that a case already filed is worthy of dismissal, the ALR is absolutely unaffected legally.
Occupational Driver Licenses (ODLs) are quickly available to most drivers by filing with a justice court, also known as a “justice of the peace.” Some vehicles, such as commercial vehicles, legally cannot be driven with an ODL, though. In some circumstances, a waiting period must pass before an ODL is considered valid. For those situations, suspensions simply must be served during the waiting period; we colloquially call these “hard” suspensions, since there is no relief.
The “right to remain silent” is one of our most famous rights. Our country has decided silence against criminal accusations is not evidence of guilt. A close corollary right is your right not to be forced to provide evidence against yourself. This is true, even if you are a suspected mass murderer, terrorist, or sex trafficker of children. To allow cops to force you to produce evidence against yourself is unconscionable and barbaric. Your first-time misdemeanor DWI arrest, however, is so much more evil than other crimes it is worthy of gutting your legal rights.
Our highest courts have uniformly ruled the concept of “implied consent” is enough to render you undeserving of your right to not participate in your prosecution. Driving has been deemed a “privilege” by our highest courts, and you are allowed to drive only if you give up rights. You don’t even need to be notified that you lose rights the moment you drive a motor vehicle. You get to learn that hard fact when you keep your mouth shut and don’t obey the cop’s request to cooperate in the investigation against you, even after you’ve been arrested.
Your refusal to obey the cop’s request for a breath or other sample could be used against you at trial. (See Transportation Code Section 724.061). This law is in place because the Rules of Evidence provide defense attorneys the opportunity to keep out this kind of evidence. Why you refused is only known to you, so it is up for debate. Refusal could be entirely unrelated to a guilty mind, but your Legislature decided to make it Texas’ policy that unfair prejudice is admissible in your DWI case. This puts you in the position of being the only one who can testify about your actual reason for refusing, meaning it has the effect of coercing you to give up your right to remain silent.
Refusing police requests to blow isn’t legally the same as refusing to answer police questions. Refusing to provide statements against yourself when asked by police is protected conduct. At trial, your refusal to talk is almost always taboo for the prosecutor to mention. The judge even specifically tells the jury they cannot use your silence against you. In DWI trials, however, the state gets to use your refusal to blow against you as evidence of your guilty conscience.
Of course, the purpose of allowing refusals into evidence is to increase the likelihood of conviction for DWI. Prosecutors get to argue your refusal, even if you were simply silent in response to the request for a sample, means you knew you were guilty and didn’t want to cooperate. That’s simply un-American and an affront to justice. I don’t write that lightly because I find it absurd and contrary to our system of justice. While it is true refusal COULD indicate a guilty mind and a desire to hide incriminating evidence, it could also indicate a sharp mind unwilling to provide a sample to be tested using an unreliable method. Something seems terribly wrong about being required to provide evidence against yourself, as well.
A DWI arrest subjects you to unique forms of legal abuse and deprivation of rights. These exceptions are contrary to historically grounded rights and principles of fairness generations of Americans have understood as fundamental. These exceptional abuses are grotesque to me and a big reason I am motivated to defend people accused of DWI. The government has systematically and unfairly stacked the deck against you.
*Urine is another form of sample cops can request, but I have yet to see one example of such a request in my 30+ years of practice.
Texas’ 50+-year old breath test program is administered by the “Scientific Director” of the Department of Public Safety. The Scientific Director is responsible for top-down decisions and everyone in the program. Roughly 700 law enforcement agencies are covered, as well as about 6,000 cops who are certified breath test operators.
Title 37, Part 1, Chapter 19 of the Texas Administrative Code contains the rules for the program. Every aspect of the program is created and administered from the Scientific Director’s office.
One of the responsibilities of the Scientific Director is to designate which breath test device(s) are approved for “evidentiary” use. In 2016, the Scientific Director approved the Intoxilyzer 9000 to replace the Intoxilyzer 5000 and Intoxilyzer 5000 EN, devices which had been in use for decades. Interestingly, only Intoxilyzer-branded products made the list, despite many being on the market and approved by other states.
The program’s Scientific Director also appoints “Technical Supervisors.” They are in charge of Intoxilyzer 9000s in each of 30 geographically assigned zones. Similarly, Breath Test Operators (BTO), typically street cops, are trained how to operate the machine and gain a certification as a BTO. They are supervised by Technical Supervisors.
Frankly, running the machine is essentially idiot-proof because the machine is all but fully automated, so much so their operator manual says it: “[s]ubject testing is highly automated.” One of the main functions for a BTO is to conduct a 15-minute observation period to reduce the possibility of mouth alcohol being present. (That’s due to a problem with breath testing: mouth alcohol can skew a result dramatically upward.)
Here’s a sample of normal questions and answers for a BTO in court regarding how the machine is operated.
Q: “You went to a class to become certified as a breath test operator? A: Yes.
Q: You have to take a retraining class periodically? A: Yes, to maintain my certification.
Q: You prepare the Intoxilyzer prior to a person blowing into it? A: Yes.
Q: What exactly do you do with the Intoxilyzer to prepare it? A: I turn it on, let it warm up, then it goes through its diagnostic checks. When it finishes its checks, I can go forward with the test.
Q: Do you input information to the machine? A: Yes. I scan the person’s driver license with the Intoxilyzer. If the license can’t be scanned, I type in the information. It beeps when it’s ready and tells us the next steps.
Q: What happens when it’s ready to take a sample? A: When the time comes to blow, I take a plastic mouthpiece from its wrapper and insert it into the end of the tube. I raise the tube to the person’s mouth and tell them to blow hard and steady until I tell them to stop. The Intoxilyzer notifies me when it has enough of a sample. After the first sample has been analyzed, a second sample is taken. I repeat the same process when the Intoxilyzer is ready for it.
Q: What do you do after the samples are complete? A: When the machine finishes its processes, it prints a result.”
As you can tell, the process from the BTO standpoint is extremely simple.
Breath test devices like the Intoxilyzer 9000 quickly provide cops with numerical evidence they can use in DWI prosecutions. In other words, breath testing makes it a piece of cake to get a number to use at trial to show an accused person was “intoxicated.”
Texas law defines intoxication as .08 g/210L (for breath) OR “not having the normal use of mental or physical faculties by reason of the introduction alcohol, another substance, or a combination of any two substances.” Whether the substance is legal is irrelevant; prescription and over-the-counter medications can render a person intoxicated.
If the state is relying solely upon the number on the breath test, that is an example of a “per se” prosecution relying upon the .08 or greater definition of intoxication. The state may also elect to use the breath test result in conjunction with other evidence to try to prove the standard definition of intoxication.
The scientific principle behind the measurement of alcohol by a breath testing device used for court evidence is straightforward. When a breath sample is blown through the machine, it passes through a sample chamber. That chamber has a source of light at one end and a light-measurement device on the other end. The difference in the amount of certain infrared light from one end of the chamber to the other represents information about a concentration of alcohol.
This difference in light from one end of the chamber to the other is caused by the absorption of light by a carbon-oxygen chemical bond in ethanol molecules as they pass through the chamber. Ethanol is alcohol for drinking.
This technique is known as “infrared spectrometry.” Light exists in a broad spectrum, and the machine measures a narrow range of that spectrum relating to ethanol, the alcohol used in beverages. A carbon-oxygen chemical bond on the ethanol molecule absorbs a bit of light as it passes through the sample chamber. The detector on the opposite end of the sample chamber from the light measures the amount of light reaching it. The information gathered is used to calculate a ratio into the grams-to-210 liters (g/210L) format.
If you want a sense of the history of breath testing, check out the National Safety Council report.
Everyone has heard of “.08.” That’s the so-called “legal limit” of alcohol. That number is part of a formula. Please don’t think you need to understand math, but the expression is .08g/210L. Another way to express it is as follows: intoxication is established when at least .08 grams of alcohol is found in 210 liters of a person’s breath.
Don’t get overwhelmed by that. It’s not a hard concept, if you break it into its parts.
First Number: .08 = grams (g) of weight of alcohol. The first part may be puzzling because few people are in the habit of thinking of a liquid like alcohol in a weight like grams, rather than a familiar volume like 12 fluid ounces of beer. You’re also probably having a hard time imagining the weight of .08 of a single gram, but there’s no need to worry.
Let’s start with what we all have seen: a small packet of Sweet ‘N Low or Splenda. If you pour the contents of the packet onto a dark table, you see one (1) gram of white powder. If you divide that pile by half, then divide that pile by half again, then divide that pile by half yet again, THEN remove about 1/3 of what remains, you have about .08 grams. It’s a tiny amount of powder and weighs next nothing. Bottom line: .08 gram is a speck of alcohol.
Second number: 210 = liters (L) of breath. Imagine you are looking for that tiny trace of evaporated alcohol in a 55-gallon drum, which is about 210 liters (L) of volume. It may be pretty hard to imagine because you wouldn’t see the alcohol any better than you could see the air.
Also, no pair of human lungs can blow 210 liters in one breath. Our lung capacity is roughly 6 liters. Since people cannot provide a 210L breath sample, breath test machines are designed to process a small breath sample.
They Add a Dash of Math. They collect data from the sample flowing through the machine, then multiply the amount of breath and alcohol by a formula which can convert the smaller volume of breath to 210L. The exact formula is not disclosed and is considered a trade secret so valuable manufacturers won’t disclose it.
In the previous breath test device Texas used, the Intoxilyzer 5000, the sample chamber was 81 cubic centimeters (also known as milliliters) in volume. That means the largest sample it could possibly see at a time is 81 cc. That volume must be multiplied by 2592 to reach 210 liters. (I do not have access to a reliable source of the 9000’s sample size, or I’d provide the associated multiple.)
Here’s a takeaway everyone should know about breath testing: the slightest imperfection at any stage of measuring alcohol in breath is multiplied thousands of times. As you can imagine, such a result can be false and devastating. This is a systemic problem and realistically cannot be avoided, due to a biological limitation of humans. The state is perfectly willing to take that risk with your freedom, reputation, and life.
An ideal objective of a breath testing program is to accurately identify alcohol levels in a person’s breath which correspond to the person’s blood alcohol levels. Alcohol in the blood is the source of alcohol in the breath and the reason for symptoms of intoxication. Thus, trying to ground the process in blood makes good sense.
Establishing a numerical relationship between a breath sample and blood concentration presents more of a challenge than you may realize. For starters, the human population has a broad range of breath to blood ratios, having been detected as low as 685:1 and as high as 3100:1. We know this from almost 100 years of extensive research about the effect of alcohol on humans. Breath to blood ratio also can vary even for the same person at different times.
Quantifying an individual’s true breath to blood ratio would require taking simultaneous samples of breath and blood, then comparing their concentrations. That’s complicated, time-consuming, and expensive. Besides, if you are taking a blood sample, why would you need a breath sample?
You might think that seemed like an unresolvable problem with breath testing. Nope. It’s not a problem at all because laws don’t have to follow the science.
The dilemma was resolved by simply setting a default “one-size-fits-all” breath to blood ratio for everyone.
All breath test devices approved in the United States use a standard breath to blood ratio of 2100:1. If the ratio is true, an equal amount of alcohol should be in 2100 units of breath and 1 unit of blood.
By programming their machines with that ratio, breath test manufacturers guarantee a sizable portion of the people who blow into the machine will have inaccurate and unreliable results. Law enforcement officials are fully aware of this problem, but breath testing is particularly convenient and easy for the government. It helps them win cases with minimal effort and expense.
To me, the breath to blood assumption in breath testing alone is enough to consider breath testing unreliable and unsuitable for purposes of evidence in a criminal case. Decision-makers for breath testing programs obviously consider it acceptable to create programs they fully know falsely elevate reported alcohol levels for some arrestees.
So, if your innate biology is such that alcohol is overrepresented in your breath, a .08 or more breath test may convict you when your blood alcohol level was truly below a .08.
That’s not to say all people are prejudiced by the assumption. Some will register higher than their true alcohol level, and some will register lower. Which one you are is based on luck of the draw.
Luck of the draw is a terrible way to gather evidence to use against someone in court. It’s even worse when dressed up as if it’s the scientific “truth.” Instead, what we have is built-in injustice to fight.
A jury trial for a breath test is an opportunity to win a case when the state wasn’t willing to offer an acceptable outcome. Risk of conviction exists, too. The stakes are high because juries are given only two options: guilty and not guilty.
We clearly want a verdict of not guilty. The way we get there is to have every juror vote not guilty. Ultimately, DWI defense lawyers need to demonstrate why jurors should have reasonable doubts about the state’s case. If jurors have a single reasonable doubt after deliberating, the law says the accused must be found not guilty, also known as being acquitted.
At a minimum, the bread and butter of defense is highlighting reasons for doubting the state’s evidence. Sometimes, we have evidence of our own to highlight, but the goal is to give jurors as much reason as possible to doubt the state’s evidence. The more sources of doubt are present, the more likely a not guilty verdict is. There is no limit on the number of or kind of reasonable doubts a juror may have, nor why they have any. Anything they can imagine is a potential source of doubt. Breath testing provides ample reasons for doubt.
One thing to note is critical: a breath test is not the only evidence in a DWI case. If other evidence can prove intoxication, beating a breath test may not help at all. For example, if a person is arrested after being stopped for driving the wrong way and narrowly avoiding a head-on collision, as well as being so drunk as to be catatonic, successfully fighting a high breath test may not help much. Even getting a breath test thrown out of court would leave the rest of the evidence to be used in court. The person still needs a lot of help from a lawyer, even if a strong defense against intoxication is not possible.
Fighting a breath test is far more likely to be helpful in a case involving a safely driving person who at least appears fairly sober during the police encounter. Also, if the breath test result is extremely high, yet video shows the person doesn’t appear to be intoxicated, a plausible argument can be made to a jury that the test was falsely high. Of course, that would be good reason to doubt the number provided by the breath test device.
Local residents of the county will be summoned to court and questioned by the judge and lawyers, then the crowd will be thinned out by their answers and by strikes each side can use to keep some people off the jury. After a jury is selected, they usually hear opening statements by each side, then evidence is presented by the state because the state has the burden of proof to prove every element of the case, including intoxication, beyond a reasonable doubt.
After presentation of evidence ends, the judge explains the law to the jury. Each side then gets to present closing statements. The jury is sent to a room where they decide the verdict, if they can. To reach a verdict, the jurors must be unanimous. If they cannot come to a unanimous decision of guilty or not guilty, a mistrial is declared, and the state must choose whether to retry the case with a new jury. If the verdict is guilty, sentencing would be next. If the verdict is not guilty, the case is over for the accused.
You should expect to have at least two witnesses in a breath test case: the officer conducting the breath test and his/her supervisor, who is in charge of the breath test machine.
In most cases, the arresting officer and breath test operator (BTO) are one in the same. A BTO has training which can be summarized as 1) observe the DWI suspect for 15 minutes immediately prior to samples being provided, so as to monitor whether the suspect burped, hiccupped, or vomited shortly before the breath test was administered; 2) turn on machine and let it warm up and do its internal checks; 3) put a new mouthpiece on the breathing tube; 4) tell the person when it’s time to blow; 5) follow the on-screen prompts of the breath test device after turning it on and letting it warm up; and 6) get the printed report of results.
The breath test supervisor will testify about the general concepts of breath testing, the breath test device itself, the review of the BTO’s records, and the supervisor’s own performance regarding the maintenance of the breath test device. You can expect to hear and/or see images of the machine and its flow chart about what happens inside the machine as a person blows into it. This witness is unlikely to have seen anything about the facts of the case, such as driving or behavior of the driver. Instead, this witness testifies primarily about the machine itself and related questions. This witness is usually a chemist who may also offer an opinion about what someone’s alcohol level was while driving, compared to the result obtained from a breath sample an hour or more later; the term for this process is retrograde extrapolation.
Juries determine the facts in the trial and apply those findings to the law, which is provided to the jury in writing by the trial judge.
Evidence does not necessarily equal proof. Evidence is what the judge will allow the jury to see or hear. Proof is the value of evidence assigned by a jury.
For example, a witness who is plainly lying or is obviously mistaken about what happened still could be allowed to testify. The content of that testimony is rightfully called evidence. However, a jury is under no obligation to believe anything a witness says. Thus, while a witness’ testimony, even that of an eyewitness or an expert witness, may conclusively state everything necessary to make a person appear guilty, a jury may consider the testimony totally false. In such a circumstance, the “evidence” amounts to no proof at all.
It takes skill and knowledge to use arguable issues effectively in court. If the attorney doesn’t understand the issues, there’s little hope he/she can argue them to the jury, much less skillfully develop the evidence during trial. Make sure you hire an attorney who is conversant about all the topics.
Some positions are used as a way to interpret evidence, but they are paired to no direct evidence. Other positions require the attorney to elicit particular testimony from witnesses and to enable the jury to consider favorable documentation, such as a chart from the expert’s training books.
Sometimes, the evidence can cause jurors to feel moral disapproval of what the state, cops, or Department of Public Safety has done. Legally, jurors are supposed to apply the facts they determine to the law presented by the judge. However, it would be naïve to think they are always as disciplined as the law expects.
For example, feelings of moral indignation can arise in jurors when they learn of assumptions the state makes which could unfairly harm people, and that may influence them to vote not guilty, even when the proof seems to favor the state. Disgust with one side can change opinions of the evidence presented by that side. When you are disgusted by someone, you tend to resist what they have to say, and that can be expressed in a verdict.
Remember, the state is responsible for eliminating all reasonable doubts from jurors’ minds. Your DWI defense lawyer should be trying to inspire and stimulate those doubts.
Here’s a partial list of topics with arguable issues. Some are topics not covered in earlier sections, but they still can apply.
Breath testing is flawed and inaccurate because it is based on a biological assumption which isn’t true: a fixed breath to blood ratio in every person. That ratio is always applied to results coming from an Intoxilyzer 9000, the breath test device Texas uses for evidence.
Evidentiary breath tests are not conducted while driving. Frequently, results come from samples submitted an hour or two after driving. The alcohol level in the arrested person at the time of driving MAY be the same as the reported result, OR higher, OR lower. The state expert for the breath test may want to apply retrograde extrapolation to the result in an effort to claim a certain alcohol level existed at the time of driving.
This is a calculation deemed to be “dubious” by one of the most respected researchers in the history of breath alcohol research. The expert witness will know the researcher’s name and acknowledge his status as more authoritative than anyone in Texas. Retrograde extrapolation is a practice fraught with problems, assumptions, and an almost ever-present lack of facts upon which to base an opinion.
Potential burping/vomiting could contaminate any sample because alcohol from the stomach would mingle with the alcohol from the lungs.
Higher breath temperature leads to higher sample result.
The state could preserve a breath sample for retesting, but they don’t.
The breath test number is not a direct measurement of a sample. It measures electrical impulses from a incredibly tiny breath sample, then mathematically turns it into a .08 format. Doing so requires multiplication of the sample by thousands of times its actual size. Even worse, the state refuses to disclose how any of it is calculated, and the law doesn’t require it.
Cops get to choose whether to ask for breath or blood samples after DWI arrests. People usually believe blood is more accurate than breath. So, if the cop chooses less reliable evidence, the jury should discount the evidence accordingly.
RFI can interfere with electronic signals in the Intoxilyzer 9000. Sometimes, powerful radios are used within a foot or two of the breath test device. For those old enough to remember it, it’s like how an electronic device affects a television antennae; you can literally see the effects of the RFI on screen. Possible sources of RFI may include police radio, electronic devices, and the location of the 9000 device.
Residual mouth alcohol can result from braces, dental work, piercings, gastroesophageal reflux disease (GERD), and dentures.
How dirty is the breathalyzer? How often has it been cleaned? Is there any carry over? Foreign contaminants can affect the device’s sensitivity.
If not, this is a fertile field of opportunity. Would you want to be convicted on the basis of a number when that number could be higher or lower by 25%? Of course not. You’d want that number to be much more reliable. Following DPS rules means it is even worse than that crazy inaccuracy. Wild variances like this are taken straight out of DPS materials.
Has the breath test device been properly maintained? Were the rules followed? How often is maintenance performed on the machine? When was the last time it was serviced before this arrest?
Breath test cases have lots of built-in problems which can be highlighted by a skilled attorney who knows DWI law and breath testing.
If a lawyer cannot intelligently discuss and explain the topic of breath testing to you, that lawyer is not someone you should hire for a DWI. If a lawyer can’t discuss the topic with a non-lawyer like you, you shouldn’t expect that lawyer to be able to explain it to a jury of non-lawyers.
A lack of knowledge or inability to comfortably discuss it would be indicators of a lawyer who does not take DWI defense seriously or is incapable of understanding. Neither is acceptable for your case and your future.
Your DWI case can affect the rest of your life, so before you choose who to hire pay careful attention to whether they can demonstrate their knowledge. You don’t want someone who talks a big game but can’t explain specific details about the Intoxilyzer 9000.
I’m passionate about defending people accused of DWI. I know drunk driving is dangerous. I also know the state tries to rig the process in its favor and needs to be fought. I like being in that fight. The state is far more powerful than the individual. Fighting an unethical bully like that is righteous work, and I find it fulfilling.
When it comes time to hire your DWI defense lawyer, you won’t blow it. Hire Phillip W. Goff.
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