Most attorneys have never won an intoxication manslaughter case. We’ve won multiple.
If you or a loved one is facing intoxication manslaughter charges in Texas, time is not on your side. While you’re reading this, prosecutors are aggressively building their case. If you want to protect your future and avoid years of time in prison, you need an attorney who has actually tried and won these cases — and there aren’t many of them in the country.
Mark Thiessen is an ACS-CHAL Lawyer-Scientist and is the only lawyer in America with his quadruple board certifications in DWI defense. He is one of very few attorneys that have tried and won intoxication manslaughter cases in a court of law, and he’s done it multiple times — including a Not Guilty verdict on a quadruple intoxication manslaughter charge.
Charges for intoxication manslaughter are the most grave drinking and driving charges you can face. Don’t face them without the best DWI attorney Houston has to offer. We’ve secured 140+ Not Guilty verdicts for clients in dire circumstances, including multiple intoxication manslaughter charges.
Call the Houston intoxication manslaughter lawyers at Thiessen Law Firm today at (713) 864-9000 or contact us online for a free, confidential consultation. We’re standing by to protect your life.
“If you do not hire Mark Thiessen to represent you in your DWI case, then you will be making a huge mistake that could personally and professionally follow you around for the rest of your life.”
Greg, DWI Client
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What is intoxication manslaughter under Texas law?
Under Texas Penal Code § 49.08, intoxication manslaughter occurs when a person operates a motor vehicle while intoxicated and causes the death of another person as a direct result of that intoxication. It is a second-degree felony — the same classification as aggravated robbery or sexual assault.
Texas law defines intoxication in three ways. Prosecutors only need to prove one:
- You lost the normal use of your mental faculties due to alcohol or drugs
- You lost the normal use of your physical faculties due to alcohol or drugs
- Your blood alcohol concentration (BAC) was 0.08% or higher at the time of the incident
Prosecutors don’t have to prove recklessness or negligence beyond your alleged intoxication; they only have to prove intoxication and causation. Once the jury accepts that you were legally intoxicated, you’re often treated as the automatic cause of the tragedy. This bias is dangerous, and your life is on the line, which is why intox manslaughter charges demand a specialist, not a generalist.
Continue reading: What is intoxication manslaughter?
Intoxication manslaughter charges and penalties in Texas
A conviction for intoxication manslaughter carries penalties that fundamentally alter the rest of your life:
- 2 to 20 years in state prison
- A fine of up to $10,000
- Mandatory 120 days and up to 180 days if any probation granted.
- Permanent felony record
- Hundreds of hours of community service
- Civil lawsuits from the victim’s family
Intoxication manslaughter charges can also be aggravated if you cause the death of an emergency service worker, firefighter, or police officer. Aggravated intoxication manslaughter charges are first-degree felonies, which can mean 5 to 99 years or life in state prison.
Intoxication manslaughter is the most serious charge you can face for a DWI in Texas. If the same incident involves injuries but not a death, you will still face intoxication assault charges, which are third-degree felonies with penalties of 2 to 10 years in prison. These charges don’t just necessitate any felony DWI lawyer. If you want to keep your future intact, you need an attorney with a proven track record of winning these extreme cases. Lawyers who know how to fight and win these cases are rare, but Mark Thiessen is one of them.
How we win intoxication manslaughter cases
To secure a conviction, prosecutors must prove two things beyond a reasonable doubt: that you were legally intoxicated, and that your intoxication directly caused the accident. Both elements can be challenged — and we’ve done it, repeatedly.
Challenging evidence of intoxication
All methods for measuring intoxication are far less reliable than prosecutors want juries to believe. As an ACS-CHAL Forensic Lawyer-Scientist — the highest scientific designation available to a lawyer — Mark Thiessen has the knowledge and experience to challenge this evidence head-on:
- Breath tests: Prone to calibration errors, operator mistakes, and interference from mouth alcohol
- Blood tests: Susceptible to contamination, improper storage, and flawed lab procedures. Mark has won multiple blood-test cases at trial.
- Field sobriety tests: Subjective, frequently administered incorrectly, and have documented accuracy issues even under ideal conditions — which an accident scene never is
Disproving causation
An accident involving a death does not automatically mean your intoxication caused it. We work with leading accident reconstruction experts to identify alternative explanations:
- Dangerous or defective road conditions
- Vehicle mechanical failure
- The actions of another driver
- Poor visibility or adverse weather
This is often the prosecution’s weakest point. The law requires them to prove your intoxication directly caused the crash — not just that you had alcohol in your system when the accident occurred.
Exposing constitutional violations
Fatal accident investigations move fast, and police often cut corners. We scrutinize every step of the process: whether the stop was legally justified, whether Miranda rights were properly administered, and whether blood was drawn with a valid warrant or lawful consent. A single constitutional violation can render critical evidence inadmissible — and potentially collapse the prosecution’s case entirely.
Continue reading: How to beat a DWI in Texas
Why choose Mark Thiessen for your intoxication manslaughter charge?
99% of criminal defense attorneys have never won an intoxication manslaughter case at trial. Mark Thiessen has won multiple — including a quadruple intoxication manslaughter verdict. That track record isn’t marketing. You can read all about them in our Notable Victories.
Mark is the only attorney in America who holds all four of the following board certifications simultaneously:
- Criminal Law by the Texas Board of Legal Specialization
- DUI Defense by the National College for DUI Defense as approved through the American Bar Association
- DUI Law by the DUI Defense Lawyers Association
- Board Certified Advocate Criminal Trial Law by the NBTA Foundation
He also holds the ACS-CHAL Forensic Lawyer-Scientist designation from the American Chemical Society — the highest scientific credential available to a practicing attorney.
These aren’t just credentials. They show thousands of hours of specialized training in the exact science prosecutors use to put people in prison for intoxication manslaughter — and the exact knowledge we use to dismantle it.
Intoxication manslaughter FAQs
What is an example of intoxication manslaughter?
A driver leaves a gathering with a BAC of 0.11 and strikes another vehicle, killing the driver. Or a person takes legally prescribed medication that impairs their reaction time, crosses the center line, and causes a fatal head-on collision. In both situations, Texas law treats the intoxication — not the behavior itself — as the cause of death.
What is the average sentence for intoxication manslaughter?
First-time offenders convicted at trial typically face 5 to 10 years in prison, though prosecutors will always pursue the maximum 20-year sentence when a death is involved. Many attorneys push clients toward plea deals in the 8 to 12 year range without exhausting all of their options at trial, but Thiessen Law Firm always fights to win your case.
How much is bond for intoxication manslaughter?
Bond typically ranges from $30,000 to $100,000, though it can be set significantly higher in cases involving multiple victims or other aggravating factors. Having an aggressive defense team working for reasonable bond conditions immediately after arrest can make an enormous practical difference while your case is pending.
How do I choose an intoxication manslaughter attorney in Houston?
Look for an attorney with actual trial wins in intoxication manslaughter cases — not just DWI experience. Look for board certifications specific to DWI and criminal law, not just general criminal defense practice. And look for an attorney who will tell you the truth about your case, including when the evidence can be challenged and when a fight at trial is your best option.
Is intoxication manslaughter the same thing as vehicular manslaughter?
No. The two are completely different charges, though in some states intoxication manslaughter is called vehicular manslaughter while intoxicated. Vehicular manslaughter in Texas requires proof of recklessness or criminal negligence, while intoxication manslaughter does not; in intoxication manslaughter cases, the prosecution only needs to establish intoxication and causation.
Need a Houston intoxication manslaughter lawyer? Mark Thiessen sets the standard.
Intoxication manslaughter is the most serious DWI charge in Texas. These charges are more like murder charges than they are charges for a DWI in Texas first offense — and you should treat them as such. The prosecution is building their case right now, and every hour without an attorney working on your defense is an hour wasted.
Thiessen Law Firm offers free, confidential consultations 24/7. Call us today at (713) 864-9000 or contact us online to start building your defense and protecting your future.
