Dallas DWI Defense Practice Areas

Dallas DWI Defense

DWI arrests in Dallas County are handled by the Dallas County District Attorney’s Office and prosecuted in the Dallas County Criminal District Courts at the Frank Crowley Courts Building, 133 N. Riverfront Blvd, Dallas, TX 75207. Dallas is one of the most active DWI enforcement jurisdictions in Texas, with arrests made by Dallas PD, the Dallas County Sheriff’s Office, DPS troopers, and the municipal departments of dozens of incorporated cities throughout the county.

A DWI conviction in Texas can follow a person into every background check, professional license application, CDL renewal, and employment decision for the rest of their life.

Deandra Grant Law has defended DWI charges in Dallas County for more than 30 years. Managing Partner Deandra Grant holds the ACS-CHAL Forensic Lawyer-Scientist designation, a Master’s Degree in Pharmaceutical Science, a Graduate Certificate in Forensic Toxicology, and is a trained SFST instructor who administers and grades the ACS-CHAL Forensic Lawyer-Scientist exam and DUIDLA Board Certification examination. Partner Douglas Huff holds the same ACS-CHAL designation. DWI forensic science challenges at Deandra Grant Law are conducted at the chemistry level.

Texas DWI Law: What the Prosecution Must Prove

Texas Penal Code §49.04 defines DWI as operating a motor vehicle in a public place while intoxicated. “Intoxicated” means either: (1) a blood alcohol concentration of 0.08% or greater, or (2) not having the normal use of mental or physical faculties by reason of the introduction of alcohol, a controlled substance, a drug, a dangerous drug, or a combination of two or more of those substances.

The second definition (loss of normal use) means a driver can be convicted of DWI at any BAC level if the prosecution proves impairment of normal faculties. This is the theory under which many Dallas County DWI cases are prosecuted, particularly when the breath or blood test result is near or below the 0.08% threshold.

Dallas County DWI Penalties

First DWI Offense — Class B Misdemeanor

• Confinement: 72 hours to 180 days in county jail. Mandatory minimum is 72 hours. Open container at the time of arrest increases the mandatory minimum to 6 days.
• Fine: Up to $2,000.
• License suspension: 90 days to 1 year.
• Deferred adjudication (HB 3582): Available for first offense with no prior DWI convictions and a recorded BAC below 0.15%. Ignition interlock required. Successful completion results in dismissal and eligibility for non-disclosure.

Second DWI Offense — Class A Misdemeanor

• Confinement: 30 days to 1 year in county jail. Mandatory minimum is 30 days.
• Fine: Up to $4,000.
• License suspension: 180 days to 2 years.

Third DWI Offense — Third-Degree Felony

• Confinement: 2 to 10 years in TDCJ. Mandatory minimum of 2 years.
• Fine: Up to $10,000.

DWI with Child Passenger — State Jail Felony

• 180 days to 2 years in a state jail facility. Fine up to $10,000. Applies when a child under 15 is a passenger, even on a first DWI offense.

Intoxication Assault — Third-Degree Felony

• 2 to 10 years in TDCJ. Fine up to $10,000. Charged when intoxication causes serious bodily injury to another person.

Intoxication Manslaughter — Second-Degree Felony

• 2 to 20 years in TDCJ. Fine up to $10,000. Bentley’s Law requires monthly support payments to the deceased victim’s minor children until age 18.

The Forensic Science of Dallas County DWI Defense

Breath testing.  The Intoxilyzer 9000 converts deep lung air alcohol to an estimated blood alcohol concentration using a fixed partition ratio of 2100:1. The actual partition ratio varies across the population from approximately 1100:1 to 3400:1. At near-threshold BAC levels, this variability is a meaningful forensic argument. The instrument’s calibration records, the 15-minute observation period compliance, and any interfering substances are all examined independently.

Blood testing.  Blood draws in Dallas County DWI cases are analyzed by the Southwestern Institute of Forensic Sciences (SWIFS) or other accredited laboratories. Chain of custody from collection through SWIFS analysis, sodium fluoride preservative adequacy, in vitro fermentation risk from improper storage, and GC-FID analytical methodology are all subject to independent review. Deandra Grant’s pharmaceutical science training applies directly to this analysis. She reviews laboratory data, not just the summary report.

Field sobriety tests.  HGN, Walk and Turn, and One Leg Stand were validated under specific controlled conditions. Deandra Grant is a trained SFST instructor. SFST cross-examination in Dallas County courts goes to the specific protocol deviations, not just whether the officer was certified. HGN has more than 47 documented causes other than alcohol. Physical conditions, medical conditions, environmental factors, and protocol deviations all affect reliability.

Retrograde extrapolation.  Where the blood or breath test was administered some time after the stop, the prosecution may attempt to project the BAC backward to the time of driving. This requires pharmacokinetic assumptions that are variable across individuals and subject to challenge. Deandra Grant’s pharmaceutical science training makes this challenge substantive rather than generic.

The ALR Deadline: 15 Days

When a Dallas County driver is arrested for DWI and fails or refuses a breath or blood test, DPS initiates an Administrative License Revocation proceeding. The driver has 15 days from the date of receiving the notice of suspension to request an ALR hearing. Missing this deadline means the suspension takes effect automatically.

Requesting the ALR hearing serves two purposes beyond the license issue.  It delays the suspension while the hearing is pending, and it compels the arresting officer to appear and testify under oath before trial. This provides an early opportunity for sworn cross-examination and fact development. Every Dallas County DWI defendant who received a notice of suspension should request the ALR hearing without exception.

Dallas DWI Practice Areas

• Boating While Intoxicated (BWI) — Sea legs phenomenon, NHTSA validation gap, Lake Ray Hubbard and Lake Lewisville enforcement
• DWI with CDL — 0.04% threshold, no occupational CDL, personal vehicle DWI triggers disqualification
• Felony DWI — DWI 3rd (2–10 years), pen packet challenges, §49.09(b) peace officer enhancement
• Intoxication Assault and Manslaughter — Causation element, EDR evidence, Bentley’s Law
• Hit and Run DWI — Failure to stop and render aid, evidence preservation
• Multiple DWI — Enhancement ladder, prior conviction proof requirements
• Underage DWI — §106.041 TABC Class C DUI vs. §49.04 DWI distinction
• Driving Under the Influence of Drugs (DUID) — Presence vs. impairment, LC-MS/MS biological specimen analysis

Why Deandra Grant Law for Dallas DWI Defense

• ACS-CHAL Forensic Lawyer-Scientist. Both Deandra Grant and Douglas Huff. Demonstrated competency in the forensic chemistry underlying DWI prosecution.
• Master’s Degree in Pharmaceutical Science + Graduate Certificate in Forensic Toxicology. Blood alcohol pharmacokinetics, GC-FID methodology, and retrograde extrapolation.
• Trained Instructor. Deandra Grant administers and grades the ACS-CHAL Forensic Lawyer-Scientist exam and DUIDLA Board Certification exam.
• 30+ years in Dallas County courts. 500+ trials to verdict statewide. The Frank Crowley Courts Building and the Dallas County DA’s office are familiar ground.
• Former prosecutor.
• 17 published law books and guides. Including The Texas DWI Manual.
• Texas Super Lawyer since 2011. AV® Preeminent rated by Martindale-Hubbell®.

If you were arrested for DWI in Dallas County, call (214) 225-7117 for a free, confidential consultation. If you received a notice of suspension, the 15-day ALR deadline is already running. Or schedule online at texasdwisite.com.

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