Fun Fact: Mark Thiessen is the second attorney in Texas to ever earn the title “ACS CHAL Lawyer-Scientist,” and the first with a principle office in Houston. At first glance, the title may sound like the product of an enthusiastic child’s imagination. But it’s actually a game-changer when it comes to defending DWI, drug, and other criminal cases.

Here, Mark explains what pushed him to seek out ACS CHAL lawyer-scientist training, and how it’s proven an invaluable investment in establishing his stellar track record.


Meredith Nudo: What first attracted you to the idea of becoming an ACS CHAL lawyer-scientist?

Mark Thiessen: Both of my parents are doctors, so I’ve always had a healthy interest in the sciences. So it comes naturally to me. As DWIs evolve, cases are becoming more and more dependent on physiology, analytical chemistry, infrared spectroscopy, gas chromatography, chemistry, pharmacology, biology, and the like. Loving science put me on this path, and this lets me excel in areas where other lawyers can’t.


MN: Give us some insight into what ACS CHAL lawyer-scientist training entails.

MT: I took four courses at Axion Analytical Labs in Chicago; Gas chromatography (Twice), Solid Drugs, and DUID [Driving Under the Influence of Drugs]. Each class lasts for 4 days, 10 hours a day. And you have to take them in order!

These classes are actually headed up by leading scientists and the best DWI lawyers in the nation… Dr. Harold McNair, Dr. Lee Polite, Dr. Jimmie Valentine, Justin and Katy McShane, Josh Lee, Ron Moore, Heather Harris – I was in good hands! But it still took me about two years to get it all done. They’re only offered twice a year, and the classes you need to take fill up really fast. Plus, you can’t take some classes without taking the others. It’s a lot of work!


MN: Are there any elements of ACS CHAL lawyer-scientist training that you found most enjoyable or valuable?

MT: Oh, the hands-on applications are absolutely invaluable. Anyone can read a book or study, but it’s the lab work that helps you best understand the material and put it into practice. Big difference between knowing what goes into gas chromatography and drug testing and actually doing it! Lab analysis helps me so much in cross-examinations, and it lets me do a better job of walking the jury through everything.

Plus, it makes it easier for me to figure out where and how human error can take place in the lab. And when they’re telling an untruth – a value to my clients, for sure! You can read all you want about the analysis, but until you’re in the lab, you have no idea what the limits are with DWI tech and the “scientists” who use it for cases. It’s like jiu-jitsu in where you can read all you want about the technical moves, but until you actually put it into practice, you’ll never really know the best way to defend yourself.

I can’t say enough wonderful things about the professors, too. They are leading the way in gas chromatography and everything’s led by three of the best attorneys in the United States. So you get science from the professors, and you learn how to win your cases based on the science as well. Application is a critical part of the curriculum.


MN: Can you give an example of a situation where ACS CHAL lawyer-scientist training is especially needed? Where are some areas where an ACS CHAL lawyer-scientist might succeed where a lawyer without such training might falter?

MT: Even a blind squirrel finds a nut every once in a while! As a lawyer, you may stumble upon a win without this training; a lawyer with this training knows where to look, so you’re going to pick up a lot more nuts.

I use my ACS-CHAL lawyer-scientist training in every single case I work on. For the most part, DAs don’t understand the science. They’ll read directly from their DA manuals and they’re rambling on and making the jury’s eyes glaze over. The DAs aren’t comfortable with presenting science to juries, so I have to circle back around and break down the science mumbo-jumbo so Average American Joe Citizen can understand. Without it, the jury will put their trust in bad science, thinking it’s like CSI when it’s not.

This is just one facet, and I wish the analyst would do what CSI is doing! Don’t just test the blood and post the results, guys! Investigate, read the report, watch the video. Right now, they’re not testing to see if the results match the evidence.


MN: How has this training benefited you and your clients?

MT: In addition to what I’ve already discussed … it helps in jury trials for sure. I can answer their questions and the questions of my clients – “How can this number be right?” – and can point out errors and help them understand the scientific process. Knowing all this actually has a calming effect on my clients, too. It’s empowering and builds confidence in the case.


MN: What are some interesting ways in which science and law converge that most people might not realize? What, if anything, threw you for a loop while you were undergoing your training?

MT: Science is everywhere. It’s in every case. This is why it’s important to me to have this background and education.

Think about it. Ballistics testing: “Did this bullet come out of the gun?” Forensic science: “How did this bullet enter the body?” Trace analysis: “Are you testing hydrocodone? Cocaine?” You have to understand trace amounts. DNA evidence, of course. Physical evidence with hair follicle testing. Fiber testing, tire treads, computer science and hacking. And, of course, human anatomy.

And what really throws me for a loop sometimes is just how much room there is for human error! The science depends on computer programs, which are extremely vulnerable to manipulation. The results are only as good as the program or the operator. If you’re plugging in the formulas, there’s room to mess around with things, to put it mildly. The user can fiddle with the data.

Contamination, too. What if they didn’t change their gloves when the started working on the case? That’s a pretty common occurrence, and the lab techs are unaware it’s even happening. If they were previously working on drug testing, and they didn’t change out their protective gear, they can contaminate later tests. You can Google this, actually. Thousands of samples here in Texas were ruined because of improper procedures. Look, if NASA can make mistakes, then it’s absolutely possible for state-run labs to make mistakes!


MN: What advice do you have for anyone considering becoming a ACS CHAL lawyer-scientist? What do you wish you had known going into the training?

MT: I wish I had done it earlier! I’m still grateful and glad that this program was put together – and I wish there were more. DNA, arson, ballistics, homicide blood spatter … I’d love to know the science behind all of it. You can never know too much. It expands the number of cases you can effectively represent.

Name of the game … at the end of the day, it’s all about being a good trial lawyer and knowing the science better than the state’s expert.

Thiessen Law Firm

Mark Thiessen is an aggressive trial lawyer best known for his devotion to justice for his clients and high rank as a DWI Super Lawyer in Texas.