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DUI Defense Lawyer San Marcos

Charged with DUI under 21 in San Marcos, Kyle, Buda, or anywhere in Hays County? Texas zero-tolerance law applies to every driver under 21. Any detectable alcohol triggers DUI — and a BAC of 0.08 or above can elevate the charge to DWI. You have 15 days from the date of arrest to request your ALR hearing. We file it the day you retain us. Former prosecutor Allison Tisdale on staff. Over 930 dismissals or rejected cases since 2021. Call 737-937-5786.

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✓ Zero-Tolerance Defense ✓ Former Prosecutor on Staff ✓ Hays County Courts ✓ Available 24/7
Litigator of the Year 2023 — DUI defense attorney Mark HullMark Hull
Expertise.com Best DUI Defense Lawyers Hays CountyMark Hull*
National Trial Lawyers Top 100 — DUI DWI defenseMark Hull — 2022
Top 40 Under 40 — Allison Tisdale former prosecutor DUI defenseAllison Tisdale — 2022
Lawyers of Distinction — underage DUI defense attorneyMark Hull
Criminal Defense Top 10 Attorney — DUI DWI Hays CountyMark Hull

*Based on the quality and quantity of reviews and average minimum rating for a law firm practicing criminal defense in Austin, TX researched by expertise.com

DUI Defense in Hays County — Zero Tolerance Means Zero Margin for Error

Texas zero-tolerance law means any detectable amount of alcohol in a driver under 21 is enough for a DUI charge under Texas Alcoholic Beverage Code §106.041 — no BAC threshold, no minimum level. But here is what most families don’t know until it’s too late: if the driver’s BAC was 0.08 or above, the DA can bypass DUI entirely and file DWI under Penal Code §49.04, which carries dramatically harsher penalties including potential jail time. In Hays County, DA Kelly Higgins’s office makes that call based on the evidence at hand.

We’ve handled underage DUI and DWI cases in Hays County and surrounding courts for over 20 years. Allison Tisdale prosecuted these cases as a Texas state prosecutor before joining the defense side — she knows exactly how prosecutors evaluate the evidence and where the cases have weaknesses. Mark Hull has practiced Texas criminal defense for over 20 years.

A DUI conviction is not just a ticket. It creates a permanent criminal record, shows up on background checks, can affect college admissions, financial aid, and professional licensing for years after graduation. We treat every underage DUI case with the same urgency as any felony. Call 737-937-5786 the day of the arrest — the 15-day ALR deadline starts immediately.

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DUI defense attorneys San Marcos — Mark Hull and Allison Tisdale, The Hull Firm

DUI vs. DWI in Texas — The Distinction That Changes Everything

These two charges are not interchangeable in Texas. DUI under §106.041 of the Texas Alcoholic Beverage Code applies only to drivers under 21 with any detectable alcohol. The standard is zero tolerance — there is no minimum BAC. A first DUI is a Class C misdemeanor: no jail time, up to $500 fine, 60-day license suspension.

DWI under Penal Code §49.04 applies to drivers of any age with a BAC of 0.08 or above, or with loss of normal mental or physical faculties. If a driver under 21 blows a 0.08 or above, the DA has the option to charge DWI instead of DUI. That changes the entire landscape: Class B misdemeanor, up to 180 days in jail, up to $2,000 fine, 90-day to 1-year license suspension, and a permanent conviction record with no deferred adjudication available.

In Hays County, which charge gets filed depends on the BAC reading, the officer’s report, and how DA Kelly Higgins’s office evaluates the case. We challenge the evidence on both charges the same way: starting with the legality of the stop, then the field sobriety tests, then the BAC testing procedure. The Fourth Amendment and Texas Code of Criminal Procedure Chapter 38 apply to both.

After a DUI Arrest in Hays County — Two Things Happen at Once

A DUI arrest triggers the same two-track process as a DWI. Both need to be addressed immediately.

15-Day Deadline

Administrative License Revocation (ALR)

The Texas DPS begins the ALR process the moment of arrest — completely separate from the criminal case. You have exactly 15 days from the arrest date to request a hearing. Miss it and the license is automatically suspended: 60 days for a first DUI, 120 days for a second, longer for refusal. We file the ALR request the day you retain us. The hearing also locks in officer testimony before the criminal case proceeds.

First DUI: 60-day suspension • Second: 120 days • Refusal: 180+ days
Criminal Case

Hays County Court

Class C misdemeanor DUI cases typically go to San Marcos Municipal Court or the Hays County Justice of the Peace courts. If elevated to Class B (third offense) or charged as DWI, the case moves to Hays County Courts at Law at 712 S. Stagecoach Trail, San Marcos. DA Kelly Higgins’s office handles the prosecution. We appear in all of these courts and know how this specific office approaches underage DUI and DWI cases.

Class C Misd. (DUI) → Class B Misd. (3rd+) → DWI if BAC ≥ 0.08
Underage DUI juvenile defense attorney San Marcos Hays County Texas

What a DUI Conviction Actually Costs a Young Person in Texas

Most families focus on the immediate penalties — the fine, the license suspension, the community service hours. Those are real, but they’re not the long-term cost. A DUI conviction in Texas creates a permanent criminal record. It shows up on every background check: employer screenings, apartment applications, professional license applications for nursing, teaching, real estate, commercial driving, and law enforcement.

For Texas State University students arrested in San Marcos, a DUI conviction can also trigger academic consequences — suspension of financial aid, removal from campus housing, and academic discipline proceedings. The university operates completely independently of the criminal courts. Even if the criminal case is resolved, the academic process continues on its own timeline.

The only way to fully protect your child’s record is dismissal, followed by expungement. If the charge is dismissed, the arrest still shows on background checks until a court issues a formal expunction order under Texas Chapter 55. We evaluate expungement eligibility on every case we close and handle the entire filing — petition, service, and order.

DUI DWI defense strategy San Marcos Hays County — stop analysis and evidence challenge

How We Defend DUI and Underage DWI Cases in Hays County

The defense strategy on an underage DUI or DWI is the same as any other criminal case: we start at the beginning and work forward. Here is how that looks in practice.

01
File the ALR request immediately

Day one. Protects the license while we build the defense and creates a discovery opportunity by locking in officer testimony before the criminal case.

02
Analyze the stop

Was there legally sufficient reasonable suspicion to pull the driver over? On IH-35 and the San Marcos city streets, many of these stops begin with minor equipment violations or speed. If the stop wasn’t legally justified, we file a suppression motion. Suppressed evidence usually means a dismissed case.

03
Challenge the BAC evidence

Any detectable alcohol triggers DUI — but “detectable” still has to be proven. We review the testing method, the equipment, the calibration records, and the chain of custody. See our page on BAC evidence challenges.

04
Evaluate DUI vs. DWI exposure

If the BAC was near or at 0.08, we look hard at the testing procedure and its accuracy. The difference between a Class C DUI and a Class B DWI is significant — we fight the more serious charge designation at every stage.

05
Engage the prosecutor strategically

Allison Tisdale prosecuted cases in Texas courts. We know what Kelly Higgins’s office values in negotiations and how they approach first-time underage offenders versus repeat DUI cases. We go in with documented legal arguments.

06
Evaluate expungement

If the case is dismissed, we immediately evaluate eligibility for expungement under Texas Chapter 55. A dismissed charge that isn’t expunged still shows on background checks indefinitely.

Texas DUI law Alcoholic Beverage Code Section 106.041 — Hays County defense

Texas DUI Law — What the Statute Actually Says

Texas Alcoholic Beverage Code §106.041 prohibits a minor from operating a motor vehicle in a public place while having any detectable amount of alcohol in their system. There is no BAC threshold — any amount triggers the statute. Unlike DWI, there is no “loss of normal faculties” component. The charge is purely about the presence of alcohol.

This zero-tolerance standard creates a different evidentiary focus than DWI. On a DWI, the prosecution has to prove a specific BAC or demonstrate impairment. On a DUI, they only have to show any detectable amount. That means the challenge often shifts from the BAC number to the reliability and accuracy of the testing method itself — and to the legality of the stop that led to the test.

Deferred adjudication — which is completely unavailable for DWI — is technically available for DUI in some circumstances. Whether pursuing deferred adjudication makes sense depends on the specific evidence, the court, and the prosecutor. We evaluate both paths: outright dismissal versus deferred adjudication followed by dismissal and expungement. The goal is always to keep the conviction off the record entirely.

Charge / Situation Class Penalties & Consequences
1st DUI§106.041 — Under 21, any detectable alcohol Class C Misd. Up to $500 fine • 20–40 hrs community service • 60-day suspension • Alcohol awareness classes
2nd DUI§106.041 Class C Misd. Up to $2,000 fine • 40–60 hrs community service • 120-day suspension
3rd+ DUI§106.041 Class B Misd. Up to $2,000 fine • 180-day suspension
BAC ≥ 0.08 (under 21)Escalates to DWI — Penal Code §49.04 Class B Misd. Up to 180 days jail • Up to $2,000 fine • 90-day–1-year suspension • No deferred adjudication
Deferred AdjudicationDUI only — unavailable for DWI Available Still creates a record — must be dismissed then expunged under Texas Ch. 55 to fully clear

Why Hire Our DUI Defense Team in San Marcos?

Mark Hull has practiced Texas criminal defense for over 20 years. He has tried DUI and DWI cases to verdict in Hays County, Travis County, Williamson County, and surrounding courts for over 20 years. Allison Tisdale prosecuted DUI and DWI cases as a Texas state prosecutor before joining the defense side. She knows exactly how DA Kelly Higgins’s office evaluates evidence, what they find compelling, and where these cases have weaknesses.

Mark Hull was recognized as Litigator of the Year 2023 by the American Institute of Trial Lawyers and named to the National Trial Lawyers Top 100. Allison Tisdale was named to the American Academy of Attorneys Top 40 Under 40 in 2022. We carry a 5.0 rating across 363 Google reviews from clients across Central Texas. We’ve achieved Over 930 dismissals or rejected cases since 2021 — including underage DUI and DWI cases in Hays County courts.

◆ Trial-Tested Criminal Defense

20+ years of Texas criminal defense experience. Hays, Travis, Williamson, and Caldwell county courts. Mark Hull.

◆ Former State Prosecutor

Allison Tisdale prosecuted DUI and DWI cases as a Texas state prosecutor before joining the defense side.

◆ Litigator of the Year 2023

American Institute of Trial Lawyers. National Trial Lawyers Top 100. Allison Tisdale Top 40 Under 40 — 2022.

◆ Over 930 dismissals or rejected cases since 2021

Across Hays County, Travis County, Williamson County, and surrounding courts — including underage DUI and DWI.

Over 930dismissal or rejected cases since 2021
5.0Google Rating (363 Reviews)
20+Years in Hays County Courts

San Marcos & Hays County DUI FAQ

The questions we hear most from parents and young drivers after a DUI arrest in Hays County — answered with specific Texas law citations and local court details.

In Texas, DWI (Driving While Intoxicated) under Penal Code §49.04 applies to drivers of any age with a BAC of 0.08 or above, or with loss of normal mental or physical faculties due to alcohol or drugs. DUI (Driving Under the Influence) under Texas Alcoholic Beverage Code §106.041 applies only to drivers under 21 — any detectable amount of alcohol triggers DUI regardless of BAC. These are two distinct statutes, two distinct charge processes, and two distinct sets of consequences. If you or your child received either charge in Hays County, call us at 737-937-5786 — we handle both.

A first-offense DUI in Texas for a driver under 21 is a Class C misdemeanor: up to a $500 fine, 20-40 hours of community service, a 60-day license suspension, and mandatory alcohol awareness classes. A second offense escalates: up to $2,000 fine, 40-60 hours community service, and a 120-day suspension. A third or subsequent DUI elevates to a Class B misdemeanor. Important: if the driver under 21 had a BAC of 0.08 or above, the charge can be filed as DWI rather than DUI — which carries significantly harsher penalties including up to 180 days in jail and a $2,000 fine. See our page on first-time DWI penalties for the full comparison.

Yes. DUI cases — like DWI cases — are built on evidence, and that evidence can be challenged. Most DUI arrests start with a traffic stop. If the stop lacked legal justification under the Fourth Amendment, we file a suppression motion under Texas Code of Criminal Procedure Chapter 38. Suppressed evidence usually means a dismissed case. Beyond the stop itself, we challenge how the officer determined there was a detectable amount of alcohol — field sobriety test administration, the reliability of any breath or blood test, and whether the officer had actual probable cause to believe the driver was under the influence. We’ve achieved Over 930 dismissals or rejected cases since 2021 across Central Texas courts including Hays County. Call 737-937-5786 the day of the arrest.

Yes. A DUI conviction creates a permanent criminal record visible on background checks. Even a Class C misdemeanor DUI is a criminal offense in Texas — it is not just a traffic ticket. Employers, landlords, and professional licensing boards can see it. If your DUI was dismissed, the arrest still shows on background checks until a court issues a formal expunction order under Texas Chapter 55. We evaluate expungement eligibility on every case we close and handle the entire filing process.

A DUI arrest triggers an Administrative License Revocation (ALR) process with the Texas DPS — completely separate from the criminal case. The minor has 15 days from the date of arrest to request an ALR hearing. Miss that deadline and the license is automatically suspended. For a first DUI, the suspension is 60 days. For a second, 120 days. For a refusal to provide a specimen, the suspension period increases significantly. We file the ALR hearing request the day you retain us — the same approach we take on every DWI and DUI case in Hays County.

Yes — and it happens more often than most parents realize. If a driver under 21 had a BAC of 0.08 or above at the time of arrest, the DA can charge DWI under Penal Code §49.04 instead of DUI under §106.041. DWI carries significantly harsher penalties: up to 180 days in jail on a first offense (vs. no jail time for a first DUI), up to a $2,000 fine (vs. $500 for DUI), and a 90-day to 1-year license suspension. In Hays County, DA Kelly Higgins’s office makes this call based on the BAC evidence and the specific facts of the arrest. If your child was arrested and you’re not sure which charge applies, call 737-937-5786 immediately.

DUI charges — as Class C misdemeanors — typically go to San Marcos Municipal Court or the Hays County Justice of the Peace courts, depending on where the arrest occurred. If the DUI is elevated to a Class B misdemeanor (third or subsequent offense), it moves to the Hays County Courts at Law at 712 S. Stagecoach Trail, San Marcos, TX 78666. If the minor is charged with DWI instead of DUI based on BAC, the case goes to the Courts at Law. We appear in all of these courts. See our Hays County courts guide for full detail on which court handles which charge type.

First: do not let them talk to law enforcement beyond providing their name and license. Invoke the right to counsel clearly and immediately. Then call us at 737-937-5786. The 15-day ALR deadline starts the day of arrest. The earlier we get involved, the more we can do — including challenging the stop, the evidence, and in some cases getting out in front of the charge before it’s formally filed. A DUI conviction at 18 or 19 can follow someone for their entire career. We treat every underage DUI and DWI case with the same urgency as any felony charge.

Unlike DWI (where deferred adjudication is explicitly unavailable), deferred adjudication is technically available for DUI under Texas Alcoholic Beverage Code §106.041 in some circumstances. However, deferred adjudication still creates a record — the charge is visible unless and until it is later dismissed and expunged. Whether to pursue deferred adjudication versus fighting for outright dismissal depends on the strength of the evidence, the specific court, and the prosecutor’s posture. In Hays County, we evaluate both paths on every case. Call 737-937-5786 and we’ll give you a straight answer on which approach makes the most sense for your specific situation.

Yes — if the charge was dismissed or if the minor successfully completed deferred adjudication and the case was dismissed, expungement under Texas Chapter 55 may be available. Expungement requires every agency — courts, DPS, law enforcement, private background check companies — to destroy the record. A conviction, however, cannot be expunged. This is why we push for dismissal or the best available outcome on every underage DUI case, and why we evaluate expungement eligibility on every closed case. If your child’s DUI was dismissed and the record hasn’t been cleared, call 737-937-5786.

DUI & DWI Defense Resources

Related pages covering every aspect of DUI and DWI defense in San Marcos and Hays County.

San Marcos DWI Lawyer

Full DWI defense hub for Hays County — all charge types, courts, ALR process, and defense strategies.

First-Time DWI Defense

What to expect on a first offense, why there is no deferred adjudication for DWI, and how to protect your record.

BAC & Breath Test Challenges

How BAC is measured, what can go wrong, and how we challenge BAC evidence in Hays County courts.

Texas DWI Laws

Full breakdown of the DWI statute, charge levels, and how Texas law applies in Hays County.

IH-35 Corridor DWI

Enforcement patterns on IH-35 through Kyle, San Marcos, and Buda — and the defense angles that matter most.

Expungement San Marcos

How to clear a DUI or DWI arrest from your record after dismissal — Texas Chapter 55 expungement process.

Hays County Courts Guide

Full guide to the Hays County Government Center, Courts at Law, Municipal Courts, and what to expect at each stage.

Hays County DWI FAQ

Answers to the most common questions after a DWI or DUI arrest in San Marcos and Hays County.

What Our Clients Say

5.0 stars • 363 Google reviews from clients across Hays County, Travis County, and Central Texas.

RL
Ronnicka Lopez
★★★★★
Google

“After two years, the case was dismissed and dropped. They made this whole ordeal easy, kept me in the loop, told me exactly what to expect. Mrs. Allison is such an amazing and sweet lady — the whole team. I see exactly why they received multiple awards for best law firm in the state.”

BS
Blake Shires
★★★★★
Google

“My case was dismissed. Mr. Hull was patient, attentive, and consistently communicative from start to finish. He explained every step and made sure I felt supported throughout. I highly recommend Mark Hull and The Hull Firm.”

SH
Shawn Hallman
★★★★★
Google

“These attorneys were responsive, intelligent, and relentless. I appreciated how they always had a plan and stayed one step ahead. If you’re facing criminal charges, you want them on your side.”

DUI Charge in San Marcos or Hays County? Call Us Today.

The 15-day ALR deadline starts the moment of arrest. DA Kelly Higgins’s office starts building its file immediately. A DUI conviction follows a young person for their entire career. Call our San Marcos DUI defense team at 737-937-5786 — 24 hours a day, 7 days a week.

Free Consultation 737-937-5786

For educational purposes only. Not legal advice. Contact us for a free, confidential consultation specific to your case.

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