November-December 2012

New to DWI prosecution?

Charles A. Boulware

Assistant Criminal District Attorney in Tarrant County

Bryan Hoeller

Assistant Criminal District Attorney in Tarrant County

Some helpful suggestions and strategies from two misdemeanor prosecutors who’ve learned a few things along the way

It was an early Sunday morning just after 1:00 a.m. when Joseph Jenkins’s Silver Dodge Ram caught Fort Worth Patrol Officer Curtis Page’s attention on Interstate-30. At that time, Officer Page was headed to the Tarrant County Jail on a routine request for assistance, but as he was nearing downtown, he noticed the truck ahead of him briefly cross both left tires over the broken white dividing line. Because this is a common driving error, Officer Page chose not to conduct a traffic stop and moved to the inside lane to pass the truck. Yet as he passed, he noticed that Jenkins was following another motorist by only a few feet. Believing this distance to be unsafe, Officer Page activated his in-car camera and positioned himself behind the defendant’s truck to further investigate this suspicious driving behavior. After observing the defendant momentarily cross the broken white dividing line a second time, Officer Page pulled him over.
    When Officer Page made contact with Jenkins, a large man in his late 20s, he quickly noticed several signs of intoxication: a slight odor of alcohol, bloodshot and watery eyes, and slurred speech. Jenkins admitted having “two beers,” and after a brief conversation, agreed to get out of his truck and perform standardized field sobriety tests (SFSTs). As he exited the truck, Officer Page observed another sign of intoxication: The defendant’s balance was slightly swayed. After observing all six clues on the horizontal gaze nystagmus (HGN) test, Officer Page began the instructions phase for the Walk-and-Turn test. However, the defendant informed Officer Page that he was unable to put pressure on his right leg because of a back injury. Therefore, Officer Page did not conduct the Walk-and-Turn and One-Leg Stand.
    The officer concluded that the driver was intoxicated and arrested him for DWI. At the station, the suspect was read his Miranda warnings and refused to answer questions. However, he did agree to provide breath samples, which showed that he had a blood alcohol concentration of 0.102 approximately one hour and 10 minutes after the traffic stop.

A typical case
This DWI fact pattern is typical and is an actual case we tried. For experienced prosecutors, a brief examination of the facts reveals several issues that must be addressed in preparation for trial. However, for new prosecutors, it’s a whole different scene. It may be your first week on the job, and you are still trying to remember what SFST and NHTSA stand for. Nonetheless, you will be first-chairing your very first DWI trial tomorrow at 9 a.m.
    Your partner is nice enough to provide you with a PowerPoint voir dire, sample direct examination, and a well-used copy of Richard Alpert’s DWI Investigation and Prosecution book, but these resources do little to relieve any anxiety as you fear looking like an amateur in trial. Add to it that the inexperienced arresting officer (who also doesn’t know what SFST and NHTSA means) will arrive at 8 a.m. for witness preparation.
    Like many others, such a situation was our initiation to DWI prosecution. We currently have a combined total of over 75 DWI jury trials, but as we reflect on those first few, there is a lot we know now that we wish we knew then. As prosecutors, we try many types of DWI cases. Some will be great State’s cases, such as those involving a wreck with a high blood test, and some will be terrible cases, such as a total refusal where the defendant politely informs the officer that a lawyer friend told him to always refuse any test. However, the cases that routinely result in a trial (rather than a plea bargain) are the ones that involve a balanced mixture of favorable and unfavorable facts. Our purpose in this article is to share approaches we have found effective in preparing for these types of trials; additionally, we will apply the approaches to two common case scenarios: the low breath test case and the breath test refusal. We will then conclude with five tips for jury selection.

Preparing for trial
Those who are new to DWI prosecution are likely new to criminal prosecution in general and still learning how to work up a case. We believe the following five tips are helpful when preparing for DWI cases.
1Educate yourself. We recommend reading Richard Alpert’s DWI Investigation and Prosecution book (available at publications) and the National Highway Traffic Safety Administration (NHTSA) SFST Student Manual (available at cover to cover.1 These two books alone provide a solid foundation for DWI prosecution.
2Learn from your fellow prosecutors. Discussing strategies and observing colleagues in trial will reveal established, effective techniques. It will also familiarize new prosecutors with the trial process.
3Develop a team strategy. A consistent message is invaluable, so coordinate with your partner on how to present evidence.
4Account for the video when planning the witness meeting. DWI cases often include lengthy roadside and/or station videos that can consume the entire meeting. Therefore, set aside plenty of time to fully discuss the case with the arresting officer.
5Make sure you can prove all the elements. Although the issue in trial is usually intoxication, elements such as “operating” or “public place” can be a major issue, so be sure to examine all the elements when evaluating your case.

Preparing the State’s ­argument
The ultimate goal in a DWI case is to prove intoxication. In any given case, however, the numerous facts that prove intoxication are not equally persuasive. Therefore, highlight those facts most favorable to the case throughout the trial by developing the closing argument first, then working backwards through the other phases of the trial.
    Establishing the closing argument first will 1) allow you to properly determine what topics need to be covered in jury selection and which facts need to be emphasized during presentation of the evidence, and 2) produce a consistent message throughout the trial so that the closing argument will be more effective.
    When organizing the closing argument, separate the evidence of intoxication into four categories: 1) subjective evidence, 2) objective evidence, 3) evidence of guilt, and 4) evidence of drinking. Subjective evidence encompasses the typical signs of intoxication that prove the first two definitions of intoxication: the loss of normal use of mental and physical faculties. Examples of subjective evidence include bad driving, difficulty following instructions, performance on the field sobriety tests, etc. Objective evidence applies to the third definition of intoxication, an alcohol concentration of .08 or more. Therefore, this evidence is present only when there is a breath or blood sample.
    The most commonly argued evidence of guilt is a defendant’s refusal to submit a breath sample. While the State should always argue this point, our experience has taught us that a breath test refusal is rarely the deciding factor when a jury reaches a guilty verdict. Those jurors that consider a breath test refusal to be strong evidence of guilt are oftentimes exposed in jury selection and struck by the defense. Therefore, it is important to identify additional evidence of guilt, such as leaving the scene of an accident or exhibiting uncooperative behavior, because it will strengthen the State’s breath test refusal argument.
    Evidence of drinking is easy to identify, but it may be limited to an odor of alcohol. However, other evidence, such as the defendant’s admissions, open containers in the car, and bar receipts, is often available. This evidence helps refute the common defense arguments that a past medical condition, the unusual act of performing the SFSTs, or nervousness explains why the defendant displayed signs of intoxication.
    Every DWI case will have some combination of these categories of evidence. As you gain experience, you may develop your own system for classifying evidence of intoxication. It’s important to be mindful, though, that the evidence can vary significantly from one trial to the next, and therefore, so should the approach. Categorizing the evidence helps identify the strengths of the case (evidence of intoxication) and its weaknesses (potential defense arguments). This approach is essential for developing an appropriate trial strategy.

Scenario One:
the low breath-test case
We now turn to applying the strategies just discussed to a low breath test case. Remember that one of our recommendations in preparing a case is to develop the closing argument first. In a low breath test case, a prosecutor’s primary focus during closing argument should be substantiating the breath test results. This is particularly important in cases like the example at the beginning of this article, so we will use it as an example.
    In this fact pattern, there are less obvious clues showing the loss of normal use, but nothing with great jury appeal. The defendant’s inability to perform the Walk-and-Turn and One-Leg Stand largely accounts for this lack of evidence, and we can expect the defendant’s back injury to come up as an explanation for why the officer observed swayed balance as well.2 In addition, while the defendant’s driving behavior can be described as careless, it was by no means erratic. There is some decent evidence of drinking (his admission of having “two beers” and the odor of alcohol) and two 0.102 breath samples. However, the defendant’s refusal to answer questions after Miranda means the technical supervisor will have insufficient information to offer an opinion based on retrograde extrapolation (an opinion which estimates the defendant’s BAC at the time of driving). As a result, the technical supervisor will likely concede on cross-examination that it’s possible that the defendant’s BAC was lower than .08 at the time of driving.
    In this type of case, prosecutors must first convince the jury that the breath test results are accurate. Some jurors cynically view the Intoxilyzer instrument as “some breath test machine used by the police,” so the State must give them confidence in the Intoxilyzer. One method is to tell the jury that you are not asking them to find the defendant guilty based on the BAC number alone but rather because of the evidence supporting that number and the stringent regulations required for its admissibility.
    Begin by explaining that breath testing has been used in Texas since 1968, so critics have had 44 years to challenge the science and validity behind it. Those challenges have been unsuccessful, and the Texas Department of Public Safety (DPS) , charged by the legislature and relying on the most up-to-date federal and industry specifications, still considers it a reliable means of determining a person’s alcohol concentration. Also note that DPS not only approves breath testing, but it also regulates it to further ensure that reliable results are produced. Follow this information with a reminder that the Intoxilyzer operator, technical supervisor, and instrument itself were all certified as required. Finally, argue that because the instrument passed all on-site and online inspections before and after the date on which the defendant provided the samples, not only was the instrument certified, but also the evidence shows it was working properly as well. To maximize the effectiveness of these arguments, emphasize these facts during direct examination so that the jury begins to feel comfortable with the breath-testing program prior to closing argument.
    After validating the breath-testing program, it is important to further substantiate the results with the State’s subjective evidence. It is OK to concede that you are not arguing that the defendant was “falling down drunk.” However, note that the peace officer was in the best position to observe the defendant, and his special training allows him to detect even those subtle signs of intoxication. This sets the stage for the prosecution’s argument that the officer was indeed trained properly—the breath tests results show his opinion was correct, and all the evidence is consistent with intoxication.
    Be prepared to answer the defense’s argument that the defendant could have been under .08 at the time of driving. In this particular case, this defendant admitted drinking “two beers.” However, he was a big man—6-foot-7 and 300 pounds—which means he obviously had more than two beers. When we tried this case, we wanted to argue that the reason the defendant was untruthful with the officer was because he knew he was intoxicated (evidence of guilt). To set up this argument, we developed testimony from our technical supervisor regarding his expertise in retrograde extrapolation and “dosing” experiments. Afterwards, we asked him if a hypothetical man with our defendant’s height and weight could drink two beers and attain an alcohol concentration of .102. Our technical supervisor confidently answered that it was “impossible.” This argument is designed to shift the jury’s focus from the possibility that the defendant was under the legal limit and back to reasons why the defendant was intoxicated. Because defendants rarely admit to drinking an amount of alcohol consistent with the breath test results, this argument is often available and effective when there is insufficient information for an extrapolation opinion.

Scenario Two:
the breath-test refusal
Statistics in our county reveal which DWI trials are most challenging. In 2010, the conviction rates for cases with breath and blood tests were 83 and 100 percent, respectively. However, the conviction rate for all DWI cases in Tarrant County was 58 percent. This sizeable decrease is attributable to breath/blood test refusal cases (45 percent conviction rate) and the dreaded total refusal (35 percent). Until counties across the state implement 24-7 mandatory blood draws, the majority of DWI trials will be refusals.
    One reason breath-test refusal cases are difficult is because the absence of objective evidence often causes juries to demand obvious signs of intoxication that are more consistent with a total loss of normal faculties. In our opinion, a well-organized “totality of the circumstances” closing argument is the most effective means for overcoming this obstacle.
    When organizing closing argument, begin by identifying the small arguments that strengthen the case. Let’s assume, in a hypothetical case, that the defendant refused to provide a breath sample, never complained of any sort of injury, and agreed to perform the full battery of field sobriety tests. He subsequently reached the decision point on all three tests after displaying four clues on the Walk-and-Turn and two clues on the One-Leg Stand. However, he still never showed significant difficulty maintaining his balance.
    This modified fact pattern is representative of many breath-test refusal cases that go to trial because it contains numerous signs of intoxication but lacks unmistakable signs of intoxication. Therefore, communicating the minor clues that factored into the officer’s determination that the defendant was intoxicated is particularly important. One example may be the time of the stop, which is relevant as evidence of guilt because the number of intoxicated drivers is relatively high at 1 o’clock on a Sunday morning. Set up this argument by asking the officer to explain the significance of the time of the stop based on his personal experience. Developing this testimony will allow the prosecution to argue that the defendant’s driving behavior at that time is another circumstance consistent with intoxication.
    Because you ultimately want the jury to reason that the multitude of subtle signs of intoxication justify a guilty verdict, a well-organized approach is essential. We have found that listing those details on a board throughout direct examination is very effective. After compiling the list, offer it as demonstrative evidence so the defense cannot alter it during cross-examination. In closing argument, use the list to remind the jury that even though the defense tried to explain away the officer’s observations, there is simply too much evidence of intoxication. Creating and strategically using this visual aid helps add persuasiveness and organization to your argument and also provides the jury another piece of evidence they can discuss during deliberations.

Jury selection
Once you have formed a trial strategy that sets up the closing argument, it is important to develop a voir dire presentation to enhance it. However, it is equally important to eliminate those jurors who will likely find that argument unpersuasive. Here are five general approaches that we believe help accomplish these two objectives:
1Undersell in jury selection. Regardless of the strength of the State’s case, prosecutors’ goal should be to exceed the jury’s expectations in trial. So it’s important to discuss evidence that is indicative of a person at the low end of the intoxication scale (barely a .08 breath test, subtle clues of intoxication, etc.).
2Promote a low standard for intoxication. Explain to the jury that the definition of intoxication was intended to include low levels of intoxication, but instead of lecturing the jury, use a hypothetical designed to have them tell you that the standard should be low. One way to accomplish this is to use the “red bouncing ball” slide on the TDCAA website (find it at dwi/videos/red-bouncing-ball.html). Most jurors respond to this slide by saying that they would want the driver to stop “immediately” (within the snap of the fingers), and agree that this prompt reaction would require all of the driver’s mental and physical faculties. You can then remind the jury during closing argument that everybody agreed the standard should be low.
3Justify implied consent when necessary. Many jurors believe the implied consent law violates their civil liberties. To help lessen this concern, inform the jury that officers do not request breath samples from randomly selected drivers; they request breath samples only after an extensive investigation has given them probable cause to believe a driver is intoxicated. This explanation shows the jury that the law is not arbitrarily applied.
4Get to know the jury. According to the National Highway Traffic Safety Administration, any given jury includes people who drink and drive. After conducting a 2008 national survey, NHTSA reported that 20 percent of the population admitted to consuming alcohol within two hours of driving in the past year, and 13 percent admitted to consuming alcohol within two hours of driving in the past 30 days.3 What does this mean? Many of your jurors are saying to themselves, “There, but for the grace of God, go I,” so it is important to discover which jurors are uncomfortable with a low standard of intoxication or may have difficulty returning a guilty verdict if they believe the defendant had only a little too much to drink. Asking the panel members if they have been personally affected by a DWI-related event is a good way to begin this discussion.
5Identify jurors that require proof of more than one definition of intoxication. Although there are three definitions of intoxication, the law requires the State to prove only one. Thus, if a juror would require proof of an alcohol concentration of .08 or more, even after believing beyond a reasonable doubt that the defendant lost the normal use of his mental or physical faculties, that juror cannot follow the law and is challengeable for cause. Therefore, prosecutors must set up a cause question that exposes this type of juror.
    For example, you could ask the following: “If, at the end of the trial and after hearing all the evidence, it was proven to you beyond a reasonable doubt that the defendant lost the normal use of his mental or physical faculties due to the introduction of alcohol, would you still require proof that the defendant had an alcohol concentration of .08 or more? In other words … who needs a number?” For breath test cases, craft a similar question to identify those jurors that cannot convict on a number alone. After presenting the question, go down the row and get a response from each juror.

Because every DWI case is unique, we are unable to address the seemingly infinite combination of issues that may arise in any one trial, so this article is by no means a comprehensive guide to DWI prosecution. The majority of your education will come from the mistakes you make in the courtroom, so always welcome feedback. If your first case is a DWI repetition though, we want to close with some advice we always receive from a caring judge before the information is read to the jury: “I don’t care what you do in trial today; just don’t read the enhancement paragraph.”


1 Both the DWI book and NHTSA’s manual are available online at the association website (the book is for sale at and the manual is a free download at www
2 We’d like to note that while Jenkins (this particular defendant) did exhibit six of the six clues for HGN, we have chosen to not discuss HGN in this article for a couple of reasons, namely, space limitations and so that we can focus on other types of evidence and strategies that readers may not have considered. A future article on HGN and its usefulness at trial is forthcoming.
3 National Highway Traffic Safety Administration, National Survey of Drinking and Driving Attitudes and Behaviors: 2008 Volume 1 Summary Report, pages 1-2 (2010).