Not Guilty v. Goliath: Conquering Giant Blood Tests Using the Disconnect Defense

Finally the day has come: Written on the face of the State’s file, in big red letters, is the blood test result. Most attorneys cringe when the lab result reveals a blood alcohol concentration over a 0.15. Now, the district attorney may legally enhance the original Class B misdemeanor Driving While Intoxicated 1st (“DWI”) to a Class A DWI, thereby increasing the punishment range to $4,000 and one year in jail.2 Additionally, jurisdictions that have a pretrial intervention program (“PTI”)3 may refuse to allow clients with over a 0.15 to participate in the program. And psychologically, most attorneys think that defending a blood test DWI case, let alone a high blood test case, is impossible.

The gravity of a high blood test result is a tremendous weight the jury must overlook. A high blood test result is an immense burden for the defense attorney to overcome. However, human common sense can relieve this massive burden, thus turning the defense attorney and jurors into modern-day heroes who together can courageously slay the giant blood test result. Using the disconnect defense (“DD”), the skilled trial lawyer will be able to empower jurors to trust their common sense and not blindly accept science or the gas chromatograph (“GC”). This article will encourage and enlighten the modern day “David” to conquer giant blood test cases and save the innocent.

Choose the Battleground

The story of David versus Goliath begins as Saul and the Israelites face the Philistines near the Valley of Elah.4

In present day, defense lawyers do not usually choose where to battle the Giant; it’s always in the courtroom. In rare cases, a trial lawyer may change the courtroom, judge, or prosecutor based on bias, past history, or other legal argument. Some territory is friendly and some hostile: You must be knowledgeable of actual particularities and rules of the Court. Additionally, know the personalities, strengths, and weaknesses of the jurisdiction, court, judge, and prosecutor. Texas Criminal Defense Lawyers Association, county listserves, mentors, and elder attorneys with stories of battles fought long ago are extremely valuable resources. In order for the DD to succeed, the battle must occur on reasonably fair ground. In the case of extremely hostile territory, the battered trial attorney may still prevail with jury nullification sympathy.

Choose the Fighter

Twice a day for 40 days, Goliath, the champion of the Philistines, comes out between the lines and challenges the Israelites to send out a champion of their own to decide the outcome in single combat, but Saul and all the Israelites are afraid. David, bringing food for his elder brothers, hears that Saul has promised to reward any man who defeats Goliath, and accepts the challenge.5

Similar to the Philistines, the State proudly presents and struts a high blood test result around, daring any defense lawyer to challenge this giant result. The defense bar, like the Israelites, must wait for the right fighter/case to challenge the State. The knowledgeable trial attorney knows that not every giant can be conquered.

The patient trial attorney waits for the right case: where the client is physically and mentally “normal” and any loss of faculty may be rationally explained. Examples of items useful in explaining a loss of physical faculties are (1) medical rec­ords of back, leg injury, inner ear problems, vertigo for poor performance on the One Leg Stand (“OLS) or Walk and Turn (“WAT”);6 (2) a height and weight chart to determine if they are 50 pounds or more overweight;7 (3) a demonstration of the client’s boots or heels in court;8 (4) a diagram of the angle of the ground;9 or (5) evidence of brain tumor, brain damage, or natural nystagmus for the Horizontal Gaze Nystagmus (“HGN”).10 The DWI trial attorney needs to show the jury how easy the Standardized Field Sobriety Tests (“SFSTs”) are to fail and how normal the client’s test results were.11 In the event the client chose to invoke his rights and refused all the SFSTs, educate through voir dire and cross-examination that invoking a constitutional right is not illegal. Additionally, help the jury recognize that any refusal was clear and coherent, and the client stood still and stable the entire time. The right DD case is one where the reasonable suspicion and probable cause for the arrest are non-egregious and rationally explainable. Make the case rest solely on the reliability and accuracy of the giant blood test.

Weapons and Armor

“Don’t worry about this Philistine,” David told Saul. “I’ll go fight him!” Saul reluctantly agrees and offers his armor, which David declines, taking only a staff, his sling and five stones from a brook.12

Notice that David was not only willing to fight, but also knew that he had better aim without excessive armor. The courageous trial lawyer not only protects the innocent through battle, but also trains for battle and is a master of legal and scientific weaponry. Any trial attorneys who want to or may want to fight DWI blood test cases should enroll in blood CLEs; enroll in DWI CLEs; educate themselves through reading articles and transcripts; and observe and assist other trial attorneys in battle.13

The educated, blood DWI trial lawyer knows gas chromatography, infrared spectroscopy, and mass spectrometry. In an effort to provide a brief generalization of headspace gas chromatography flame ionization detection (HSGC-FID), it is important to start with the actual blood draw site. The physician, qualified technician, chemist, registered professional nurse, emergency medical technician, or licensed vocational nurse14 must use a sterile solution, not ethanol, to cleanse the site/arm in concentric circles.15 Usually the drawer uses iodine, betadine, or povidone-iodine. The drawer then inserts a needle in the vein of the arm and blood is drawn into a pressurized test tube called a Vacutainer.16 The Vacutainer is usually grey topped and may contain a variety of chemical components, so it is important to research the manufacturer of the Vacutainer and the additives.

Most grey-topped BD Vacutainers contain an anti-coagulant (Potassium Oxalate) and preservative (Sodium Fluoride)17 and must be properly inverted 8–10 times.18 Arguably, if these steps are not strictly followed then the third prong of Kelly is violated.19 Most jurisdictions draw blood into two Vacutainers, which are then packaged and transported to a laboratory. The chain of custody is critical to determine how the blood was transported and ultimately delivered—i.e., whether it takes days to get to the lab, sits in the trunk of a car, sits in an unsecure location, is shaken, is contaminated, etc. Once at the lab, the lab’s chain of custody should list every time the Vacutainer is moved or analyzed.

Next, an analyst will prepare the client’s blood for testing by adding the client’s blood to N-Propanol and a salt in a smaller vial. N-Propanol is called the standard since it should never exist in a living person’s blood. Note that the analyst programmed the GC/computer before the test is even run to know exactly how much N-Propanol is being analyzed. The client’s mixture is then capped and heated. According to Henry’s Law, “At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.”20 Or in plain language, the blood alcohol concentration should be the same in the gas above the liquid at equilibrium. The vial is then placed in an autosampler, and the autosampler then withdraws an amount of headspace gas (HS) with an automated needle and injects the gas into the injector port of the GC. The carrier gas, usually either helium or nitrogen, helps push the sample through the column(s). Inside the column(s), ethanol and N-Propanol are separated from each other due to their unique attractiveness (retention time) to the walls of the column. Then, ethanol and N-Propanol will come out (elute) at a particular time and order based on their unique retention times. The compounds will then travel through a flame ionization detector (FID).

The FID is connected to a computer that registers the burst in flame and transmits that detection into a graph (chromatogram). The source code in the computer then measures the area under each peak on the chromatogram. The computer measures the area underneath the N-Propanol peak and has been programmed to relate that particular area with the amount of N-Propanol added by the analyst. The computer then uses that calculation as the benchmark to measure the amount of ethanol present in the sample.21 In the end, the GC does not directly measure the amount of ethanol in the sample, but rather indirectly measures the amount of ethanol in relation to an alleged known, exact amount of N-Propanol.22

There are many intelligent lawyers and scientists, but their intelligence may confuse juries. Real experts must be able to teach basic GC to the average Texan. The trial lawyer knows that a case is not won by making the expert, judge, or prosecutor look uneducated. The skilled trial lawyer is able to teach this complex science and measurement in a way the everyday juror can understand. Although the burden rests with the State to prove the blood result is reliable and accurate, most often the defense counsel must actually simplify the science in order to make any problems with the analysis understandable.

Strike Swiftly, Accurately, and Without Mercy

David and Goliath confront each other, Goliath with his armor and shield, David with his staff and sling. David hurls a stone from his sling with all his might and hits Goliath in the center of the forehead.23

Like David, the trial attorney knows the power of the DD. In order to throw a rock from a sling, you must first place the rock in the sling, then twirl the sling very fast, and ultimately release the rock at the precise moment with precision and accuracy.

a. Getting the Sling Ready

The preparation of the sling comes in voir dire. The trial lawyer needs to sow the seeds of doubt in the jurors’ minds. Incorporate a discussion about what people may look like at high alcohol concentrations. Most jurors will agree that they could not determine if a stranger was a 0.08. Take them one step further: What about a 0.16, twice the legal limit? About half of the jury will say they could tell if a stranger was twice the legal limit because that person will be stumbling, slurring his speech, and obviously drunk. Then, ask how many jurors could tell if someone was 0.24—three times or more over the legal limit? It may be easier to ask if any juror could not tell if someone was that intoxicated. When questioned about signs of intoxication at three times over the legal limit, jurors often say vomiting, passing out, or absolutely belligerent or wasted behavior.

Be wary of the juror who submits tolerance as an excuse for looking normal. Explain that tolerance only masks ordinary actions one does while intoxicated. So in the case of SFSTs—abnormal exercises—tolerance will not mask the effects of alcohol.24 Help the jury realize that people exhibit tolerance by being able to walk and talk normally while intoxicated, and that these are things they “practice” when they are intoxicated. Unless the client is practicing SFSTs while intoxicated, tolerance cannot mask the effects of alcohol on abnormal exercises such as the SFSTs. Additionally, ask the jury this: What if you went to dinner, had a couple glasses of wine, were pulled over and passed the SFSTs, do you go home, or does the State get to say you have a tolerance? Tolerance is eating your cake and having it too. Make the jury scared and skeptical of the State arguing tolerance.

Since we are not allowed to discuss the facts in voir dire, relate the information the jury just gave you about extreme alcohol results with a common household machine—i.e., stopwatch, thermometer, or a bathroom scale. Next, show them a simple picture of an obese man, a child grinning and playing outside, or a very skinny person. Then ask: What if I told you this. Right now, this obese person ran a 4.5-second 40-yard dash according to my stopwatch; the child has a 114-degree temperature; or the skinny person weighed 350 pounds on my bathroom scale. What would you say to me? Most say: No way!

Now, relate dire consequences with this measurement: What if we bet $10,000 or jail time that the measurement is right, and I am telling you, “Trust me, it is accurate and reliable.” Ask the juror: What do you want to happen? Most jurors will shout out: Prove it! In any DWI case, the State will argue the blood result of intoxication is per se at 0.08, but the State must prove the result is accurate and reliable beyond a reasonable doubt. Let the jury recognize the need for proof over blind acceptance of a machine’s reading.

Next, relate the common everyday machine example to problems with blood testing. Go down the row of jurors relating blood testing issues one by one and ask them how it makes them feel. For example with the stopwatch: What if I told you I was paid by the parents of this student to time how fast he ran the 40-yard dash in hopes of getting a track scholarship to a Division I school? I have timed tens of thousands of students and never been wrong. Only I would ever know if I was wrong. I use my stopwatch and I line up all the kids I’m timing, then I time them all and get a printout at the end. I know the order of the kids, so based on that order I can tell you what the student ran. The order does not printout the student’s name, but actually a unique identifier that I supplied them. Also, my stopwatch does not actually time the student, rather it measures their speed in relation to how fast an NFL running back ran the 40, and I program that speed to be 4.5 because I know that running back ran that fast, absolutely. Also, I have no idea whether the student even looks like a Division I track star. Lastly, when my fellow employee checks my work he just reviews my numbers and is not physically present during the timing. Break down these statements by asking a juror one statement at a time: Would that make you feel more or less comfortable with my procedure? In the end, after all the statements are exposed, ask the jurors this: Would you trust my result or do you want that student to prove it?

b. Twirl the Sling With Everything You’ve Got

Eighty to ninety percent of jurors make up their mind after opening statement.25 In opening, tell the jury what really happened, tell them how normal the client looks and where they can clearly see normal mental and physical faculties. Freely disclose that the case is all about the accuracy and reliability of the blood test result. Tell the jury that the blood test result is an indisputable conflict with the tangible evidence. This indisputable conflict of a ridiculously high number versus the client’s normal mental and physical faculties defies logic and common sense.

Use cross-examination of the officers to minimize any alleged loss of the client’s mental and physical faculties. Again, show the jury how unfair the SFSTs are by educating the jury on how the tests are actually administered. Expose that the officer took a 40-hour course to be certified by the National Highway Traffic Safety Administration (“NHTSA”) to administer SFSTs. Additionally, the officer was only graded at the end of the course. The officer was not graded on the first day after just learning how to administer the test only one time. And, if the officer missed 3 questions on the certification test, he did not fail. In fact, the officer received credit for every correct answer. Moreover, the officer has never taken a test where he did not receive credit for correct answers. If you have a 100-question test and miss 3, what is your score? Would you ever take a test where you did not get credit for the answers you got right? Most seasoned officers will volunteer that NHTSA requires this type of grading, and “scientists” developed the grading system. A good jury will recognize the unfairness of the NHTSA grading method.

The jury should also truly understand these tests in case they wanted to try them, after the trial is over. Start with either test and walk through the exact instructions and break down how many specific instructions are given in each test (15 for walk and turn, 13 for one leg stand).26 How many times did the officer give the client the instructions? How many times does the officer demonstrate the test for the client? Does the officer allow the client to practice before being graded? Was the client allowed to practice for over 40 hours before he was graded on his administration of these tests, like the officer was allowed to do? Is the client told the clues the officer is looking for? Did the officer tell the client it only takes 2 clues to indicate intoxication? Did the officer tell the client that injuries, age, or weight may affect the results? Make sure to write these answers on your display board for each test. Next, walk through each clue and show the jury how meticulous and subjective the clues really are.

Furthermore, attack the Horizontal Gaze Nystagmus (HGN) test by educating the jury that the officer did not state any clues on the video and only wrote down these clues once the client was arrested for DWI. Additionally, NHTSA does not define how far the eye must jerk in order to be counted as a clue, or how many times the eye must jerk. Another issue, the client usually gets every single clue on the HGN, but rarely triggers all clues on the Walk and Turn or the One Leg Stand—tests where the jury can see the clues with their own eyes. In fact, the jury must “trust” that the officer saw all of the clues on the HGN. Most jurors will appreciate the defense attorney revealing just how easy these tests are . . . to fail.

And lastly, ask each witness whether the client urinated themselves or asked to use the restroom. The existence of a high blood alcohol concentration generally means large volume of alcohol consumed. Every experienced drinker knows that it is only a matter of time until you have to urinate frequently because your body cannot physically retain all of the liquid.27

Now the case is all about the reliability and accuracy of the blood test . . .

c. Deadly Strikes

1. The Blood Drawer

David hit Goliath only once in the forehead, which caused the giant to fall. Cross-examination of the blood drawer should revolve around proper site preparation and handling of the Vacutainers. Remember a physician, qualified technician, chemist, registered professional nurse, emergency medical technician, or licensed vocational nurse28 may draw the blood. This area of questioning is ripe for Kelly challenges that the proper forensic procedure was not correctly performed in this case. However, if the drawer did proper inversions or cleansing technique, do not be afraid to admit and congratulate them. Not only does it show knowledge of phlebotomy on your part, but also shows that you are not attacking every witness and just “throwing spaghetti at the walls,” as the State likes to argue.

A real and valid problem with improper cleansing of the site is the chance of candida albicans affecting the blood result. C. albicans is a yeast that can cause falsely elevated ethanol levels in blood.29 It is absolutely necessary that the drawer properly cleanse all of the dirt, bacteria, yeast, or fungus from the site of needle insertion. C. albicans contamination is a hotly contested defense with literature existing from both the State and defense point of view. Bottom line, the analyst never tested for C. albicans and assumes that: (1) the nurse properly cleansed the site; (2) no C. albicans was introduced externally into the sample; and (3) no C. albicans resides inside the client.

Whether the Vacutainers were properly inverted can affect the blood results as well. The preservative and anticoagulant must be mixed homogeneously throughout the blood. If not, then the blood can coagulate (clot) or ferment. The definition of ethanol concentration in blood is based on grams of ethanol per 100 milliliters of whole blood, not serum or plasma.30 If the blood clots, then serum will begin to form.31 Since ethanol is hydrophilic, it will stay in the serum and produce a falsely elevated ethanol result (18–59% high) when the serum is tested, and not whole blood.32 Whoever inverts the Vacutainer is responsible for proper inversion technique: two full 180-degree turns is one inversion.33 If the inverter of the tubes plays games about the ease of mixing liquid and powder, ask how many times they need to stir the cocoa, Tang, or baby formula into the liquid before it is homogeneous.

The blood analyst assumes proper cleansing technique and inversions are performed on the Vacutainers. The blood drawer and person who inverted the tubes are prime targets for blood suppression based on the third prong of Kelly. Additionally, the drawer very rarely remembers the client and should not have any opinion of intoxication. Lastly, this witness will likely agree the client never asked to use the restroom.

2. The Analyst

The Analyst is the smartest and most dangerous witness of a blood test trial. The State proudly displays the analyst as the smartest person in the room, knowing far more about science than everyone else. In fact, some analysts may even refer to themselves as “scientists.” The trial attorney should read the résumé and classes taken by the analyst and politely educate the jury on the true foundation of their knowledge. For example, a certain Harris County analyst attended the following classes: “How to Be a Good Expert Witness,” “Expert Testimony Training for the Prosecutor and Scientist—Part 1,” “Expert testimony Training for the Prosecutor and Scientist—Part 2,” and “Law and Forensic Science.” Additionally, this same analyst has prepared tens of thousands of vials and currently testifies that she has never made a mistake. Furthermore, this same analyst only testifies on behalf of the State and has never testified that the result is inaccurate or that the State has ever made a mistake. The jury needs to recognize that this analyst is not an independent “scientist” who works for an independent lab. Rather, this is the State’s puppet.

After exposing an analyst’s bias, begin the cross-examination with basic science every juror learned. Begin with the Scientific Method and write it on a butcher pad for all the jurors to see:

(1) Develop a question;
(2) Conduct background research;
(3) Develop a hypothesis;
(4) Test the hypothesis through experimentation;
(5) Analyze the data;
(6) Draw a conclusion; and
(7) Report the results or retest.34

Commit the analyst that there is no “Trust Me” step.35 In fact, if conducting true science, the analyst should adequately document the entire test so that it can be reproduced and the exact same results achieved. There is no “trust me” in science.

Once the Scientific Method is established, walk the jury through the blood testing procedure. Make sure to point out that the analyst assumes the blood draw was done properly and the proper inversions occurred. Discuss the issue of C. albicans and reveal that the analyst never tested for C. albicans. Next, move through the process of gas chromatography while simplifying it for the jury. After the jury, the Court, and State understand gas chromatography, begin revealing the problems with the individual GC/machine. It is absolutely necessary that all discovery materials are reviewed by a defense expert.36 The defense expert will often times find problems with the State’s lab, but may ultimately conclude that any problems would not affect the result in the case. The skilled DWI trial attorney knows how to develop those simple problems into big reasonable doubt. The DD does not require a defense expert.

One of the biggest fears of any analyst or laboratory is switching samples. Unlike breath testing, blood is not tested one sample at a time. Blood samples are loaded on to a tray and numerous subjects are placed into an autosampler, which feeds into the GC. This differs from breath testing where the officer administers the breath test to one subject at a time and the result comes out immediately. What if 35 people blew and a printout of the results in the order received was produced? Better hope no one messed up that order.

Ask the analyst if the technical reviewer who is on the blood test result physically observed the order and double-checked the order. Usually, just one analyst makes all 70–90 vials at a time and places them in the machine. Most analysts—when asked “How do we know you didn’t mess up the order?”—will simply say, “Trust me,” or, “I don’t make mistakes.” Obviously, this is a moment to refer back to the basic scientific method and remind the analyst there is no “trust me” in science. Furthermore, most analysts do not even write the client’s name on the vial in the autosampler; most write only the case number or some other numerical identifier.

Examine the entire batch/run that includes the client’s sam­ple. Look for similar numbers, look for possible switches with 0.000s or under 0.08, and look at the samples just before and after the client’s. Blood testing procedure has a tremendous possibility for human error in switching vials. Ask the analyst how many blood sample vials they have prepared versus how many times they have testified at trial. What is the likelihood that anyone would ever question or confront them about a mistake? Who would know if they switched vials? The only way to get caught would require the right defense lawyer willing to try a DWI blood case and an innocent client professing innocence in order to even challenge whether a mistake was made.

If defense counsel knows the science and assumptions of retrograde extrapolation, retrograde the result as high as possible with as many drinks possible to have occurred at the time of driving. Afterwards, cross-reference the result with Dubowski’s table on common characteristics at that level.37 Challenge these characteristics with actual tangible evidence in the case: the video and offense report. Ask the analyst if the client looks like that ridiculous number on the video. Most, if not all, never watch the video. The trial lawyer should pause and look at the jury. The jury should understand that the puppet is willing to testify to intoxication without even watching the video. And then finally ask the analyst: “If the result does not match the evidence, what is prohibiting the analyst from retesting the blood for C. albicans and the client’s DNA?”

Finish the Fight

Then David ran over and pulled Goliath’s sword from its sheath. David used it to kill him and cut off his head.38

Exhausted from battle, the closing argument is time to finish off the giant blood test. The jury requires courage and righteous indignation to send the client home. Who is really the villain? Is it the high blood test? No. It is the government, working together with law enforcement, accepting bad science from a law enforcement lab, and convicting the innocent on biased science. The ridiculously high blood test result that does not match the tangible evidence defies common sense. The trial lawyer should remind the jury that it was revealed in opening statement that an indisputable conflict between the blood test result and what jurors would hear and see would exist, and yet the State still has no excuse. An indisputable conflict in the evidence equals rea­sonable doubt. The fact a person can be that intoxicated, yet look that normal, and never have to use the bathroom defies common sense and science. Either the client’s body defies the laws of science and they are an alien, or the result is wrong.

Texans need independent labs for forensic science—a lab willing to acknowledge a mistake without fear of losing jobs or incurring enmity from a police agency and district attorney’s office. Scientists and labs make mistakes, but only independent scientists admit mistakes. Real science is not expected to be per­fect. Empower the jury to stand up for the people of Texas. The defense lawyer cross-examined every witness, fought the DA, and dealt with the judge without ever asking for help. Now is the time to ask the jury for help. Ask the jury to help you stand up for your client and the people of Texas. Remind the jury that when this case is over, they will remember their verdict for the rest of their lives. Remind the jury that when they go home and their friends and family ask about the case and if there was anything wrong with the blood, if they sit silent, they know deep down they are not telling the whole truth. The jury can and should be proud of a “not guilty” verdict. Ask them to stand proud and remember the day they stood up for the people of Texas against the giant government. A “not guilty” verdict is a giant cry for better forensic science in Texas.


1. Thank you to my associates, Mark Metzger and Shelby Burns, for their editing.

2. Texas Penal Code Section 49.04(d) states, “If it is shown on the trial of an offense under this section that an analysis of a specimen of the person’s blood, breath, or urine showed an alcohol concentration level of 0.15 or more at the time the analysis was performed, the offense is a Class A misdemeanor.”

3. Harris County.

4. Holy Bible, 1 Samuel 17:2–3.

5, Holy Bible, 1 Samuel 17:8–27.

6. “The original research indicated that certain individuals over 65 years of age, back, leg or inner ear problems, or people who are overweight by 50 or more pounds had difficulty performing this test.” National Highway Traffic Safety Administration (“NHTSA”) Student Manual, Section VIII, p. 14.

7. Id.

8. “Individuals wearing heels more than 2 inches high should be given the opportunity to remove their shoes.” Id.

9. Requires a reasonably dry, hard, level, and non-slippery surface. Id. at 13.

10. Nystagmus may also be caused by certain pathological disorders. They include brain tumor and other brain damage or some diseases of the inner ear. Id. at 4.

11. See “11 Essential DWI Trial Tactics,” Mark Thiessen, HCCLA The Defender, Winter 2013, pg. 26. See also TCDLA Voice for the Defense, May 2014.

12. Holy Bible 1 Samuel 17:32–40.

13. Author recommends American Chemical Society (ACS) programs at Axion Laboratories; National College for DUI Defense (NCDD) Harvard Summer session; NCDD/TCDLA Mastering Scientific Evidence; TCDLA DWI seminars. Mark Thiessen cell is 832-654-3058; call me anytime for transcripts or articles ().

14. Tex. Transp. Code § 724.017 (West 2011). House Bill 434 (Effective September 1, 2013)

15. Concentric Circles—start from center of site and counterclockwise in ever-widening for 2–3 inches in diameter. Ruth E. McCall, Phlebotomy Essentials, IV:11 pgs. 280, 408 (4th ed. 2008).




19. Kelly v. State, 824 S.W.2d 568 (Tex. Crim. App. 1992).


21. A huge thank you to Axion Analytical Laboratories in Chicago, IL., Professor Harold McNair, Dr. Lee Polite, Justin McShane, Josh Lee, Katy Kennedy, the staff at Axion, Deandra Grant, Grant Scheiner, J. Gary Trichter, Troy McKinney, Doug Murphy, Glenn Neely, NCDD, and TCDLA for helping me understand gas chromatography.

22. Thanks to Justin McShane for everything.

23. Holy Bible 1, Samuel 17:48–50.


25. Johnson, James, “Jury Argument—Winning Techniques,” Michigan Bar Journal, Vol. 90, No. 3, p. 36 (March 2011);

26. See NHTSA Standardized Field Sobriety Testing Student Manual, August 2006, pp. X-3–5.

27. Except this one time where a lawyer, who shall remain nameless, proved me wrong, kind of.

28. Tex. Transp. Code § 724.017 (West 2011). House Bill 434 (Effective September 1, 2013)

29. Chang, J. and Kollman, S. E., “The effect of temperature on the formation of ethanol by candida albicans in blood,” Journal of Forensic Sciences, Vol. 34, No.1, pp. 105–109 (January 1989); Blume, P. and Lakuta, D. J., “The effect of microbial contamination of the blood sample on the determination of ethanol levels in serum,” American Journal of Clinical Pathology, Vol. 60, No. 5, pp. 700–702 (November 1973).

30. Texas Penal Code § 49.01.


32 Edward F. Fitzgerald, Intoxication Test Evidence, § 4:11.1, at 136 (1993); Edward F. Fitzgerald, Intoxication Test Evidence, § 19:13, at 9-12-13 (2d ed. 1995).



35. Thanks to Justin McShane for this approach.

36. Amanda Culberston, Gary Wimbish, or Janine Arivascu.

37. See Dubowski, Kurt M., “Alcohol Determination in the Clinical Laboratory,” Am. J. Clin. Pathol. 74: 747–750 (1980).

38. Holy Bible, 1 Samuel 17:50–51.

Mark Ryan Thiessen
Mark Ryan Thiessen
Mark Thiessen is a criminal trial lawyer and the Chairman/CEO of the Thiessen Law Firm in Houston, Texas. Mark is Board Certified in (1) Criminal Law by the Texas Board of Legal Specialization; (2) DUI Law by the DUI Defense Lawyers Association; and (3) DUI Defense Law by the National College for DUI Defense through the American Bar Association. Mark earned the American Chemical Society-Chemistry and the Law (ACS-CHAL) Forensic Lawyer-Scientist designation, which is the highest form of scientific recognition available for lawyers. Mark is a frequent legal seminar lecturer, author of numerous published legal articles, and a faculty member for various organizations. Mark is the current DWI Committee co-chair and on the Board of Directors for Texas Criminal Defense Lawyers Association (TCDLA), President and on the Board of Directors for Harris County Criminal Lawyers Association (HCCLA) and a Charter Member and Director for DUI Defense Lawyers Association (DUIDLA). Mark is a 7 time Texas Super Lawyer and in the Top 100 Super Lawyers in Houston (2017-19). In 2019, Mark was the only DWI lawyer to be named to the Top 100 Super Lawyers in all of Texas. Mark has won DWI cases from total refusals up to quadruple intoxication manslaughter. and 832-654-3058.

Mark Thiessen is a criminal trial lawyer and the Chairman/CEO of the Thiessen Law Firm in Houston, Texas. Mark is Board Certified in (1) Criminal Law by the Texas Board of Legal Specialization; (2) DUI Law by the DUI Defense Lawyers Association; and (3) DUI Defense Law by the National College for DUI Defense through the American Bar Association. Mark earned the American Chemical Society-Chemistry and the Law (ACS-CHAL) Forensic Lawyer-Scientist designation, which is the highest form of scientific recognition available for lawyers. Mark is a frequent legal seminar lecturer, author of numerous published legal articles, and a faculty member for various organizations. Mark is the current DWI Committee co-chair and on the Board of Directors for Texas Criminal Defense Lawyers Association (TCDLA), President and on the Board of Directors for Harris County Criminal Lawyers Association (HCCLA) and a Charter Member and Director for DUI Defense Lawyers Association (DUIDLA). Mark is a 7 time Texas Super Lawyer and in the Top 100 Super Lawyers in Houston (2017-19). In 2019, Mark was the only DWI lawyer to be named to the Top 100 Super Lawyers in all of Texas. Mark has won DWI cases from total refusals up to quadruple intoxication manslaughter. and 832-654-3058.

Previous Story

Science and the Narrative in Criminal Defense

Next Story

Jury Persuasion in Criminal Cases: Utilizing “Solution Selling” Techniques

Latest from Features