DWI Defense
Paul F. Tu Attorney at Law does not treat a Texas DWI charge like a routine traffic case. As a former Fort Bend County prosecutor and seasoned trial attorney, Paul F. Tu knows how the State builds these cases and where they break.
Illegal stops, unreliable field sobriety tests, unsupported claims of operation, and flawed breath or blood evidence can all destroy the prosecution’s case. Every detail is challenged, every weakness is pressed, and every defense is prepared for court from the beginning.
Defending Against an Illegal Traffic Stop
A DWI prosecution can fail when the initial stop was unlawful. Police need reasonable suspicion based on facts. A hunch, an unverified report, or innocent driving conduct is not enough.
A Texas DWI lawyer compares the report with video, dispatch recordings, and roadway conditions. Video may disprove alleged weaving, show no traffic violation, or establish that officers extended the detention too long.
Counsel can move to suppress evidence under the Fourth Amendment and Texas Code of Criminal Procedure Article 38.23. If the stop or detention was illegal, the State may lose statements, sobriety tests, observations, and chemical evidence.
Defending Against Claims That the Accused Operated the Vehicle
The State must prove operation. Being intoxicated inside or near a vehicle does not automatically establish DWI.
This defense applies after crashes, in parked-car arrests, when several people could have driven, or when police saw no movement. Prosecutors must connect the accused to conduct affecting the vehicle’s functioning, not proximity or assumption.
The best DWI defense attorney examines:
- Whether the engine was running and where the keys were found.
- Whether the vehicle was operable, legally parked, disabled, or damaged.
- Whether anyone saw the accused drive or another person had vehicle access.
- Whether any admission was voluntary and reliable.
- How much time passed between the alleged driving and police arrival.
Later impairment signs may not prove intoxication while driving. Circumstantial evidence is permitted, but speculation cannot satisfy the State’s burden.
Defending Against Field Sobriety Test Evidence
Field sobriety tests are officer-controlled roadside exercises, not automatic proof of intoxication. Their value depends on standardized instructions, correct administration, fair conditions, and accurate scoring.
A lawyer reviews the video frame by frame and compares the officer’s conduct with training standards. The defense may expose uneven pavement, poor lighting, unsuitable footwear, age, injury, fatigue, anxiety, illness, or balance conditions. It may also identify incomplete instructions, improper demonstrations, incorrect timing, faulty stimulus movement, or exaggerated clues.
Under Emerson v. State, horizontal gaze nystagmus evidence depends on proper administration by a qualified officer. The defense can attack the officer’s certification, medical screening, positioning, timing, and claim that eye movement proves a specific alcohol concentration.
Defending Against Breath-Test Results
A breath-test result is only as reliable as the machine, operator, observation period, maintenance history, and timing.
A Texas DWI attorney can obtain calibration records, inspection reports, repair histories, operator credentials, testing logs, and testing-room video. Those materials may expose maintenance failures, procedural deviations, or unreliable results.
Breath-test defenses may include:
- Failure to complete or document the required observation period.
- Mouth alcohol caused by reflux, belching, vomiting, dental work, or recent substances.
- Calibration, maintenance, environmental, software, or operator problems.
- Results that vary beyond an acceptable range.
- A substantial delay between driving and testing.
- Rising alcohol concentration after the vehicle was operated.
Even a reading above 0.08 does not end the case. The prosecution must connect that number to driving. A delayed test may show only the concentration at the police station, not during operation.
Defending Against Blood-Test Results
Blood evidence must survive attacks on both the seizure and the science. Counsel examines the warrant, affidavit, collector’s qualifications, tube lot, preservatives, labeling, storage, chain of custody, laboratory method, quality-control data, and analyst calculations.
A lawyer may seek suppression when officers obtained blood without a valid warrant, voluntary consent, or recognized exception. State v. Villarreal confirms that implied-consent law does not automatically authorize every warrantless, nonconsensual blood draw.
Scientific challenges may expose an unsupported warrant affidavit, expired materials, contamination, fermentation, mislabeling, storage failures, broken custody records, laboratory deviations, or measurement uncertainty. Retrograde extrapolation estimates an earlier concentration from a later sample. Under Mata v. State, that opinion requires a reliable foundation. Drinking time, food intake, absorption, elimination rate, testing delay, and the number of samples can defeat the calculation.
A laboratory certificate is not untouchable. The analyst must explain the procedures, assumptions, deviations, and limits behind the reported number.
Defending Against Drug and Prescription-Medication Allegations
The presence of a drug or medication in blood does not establish intoxication. Prosecutors must connect the substance to a loss of normal mental or physical faculties.
A Fort Bend County DWI lawyer reviews dosage, prescription records, timing, therapeutic ranges, active compounds, inactive metabolites, interactions, toxicology methods, and any drug-recognition evaluation. The defense may show that a substance was legally prescribed, therapeutic, inactive while driving, or unrelated to the officer’s observations.
Fatigue, anxiety, injury, illness, or a neurological condition may explain alleged impairment. Cross-examination can expose an officer who lacks the medical basis to connect a detected substance with impaired driving.
Defending Against the State Before Trial
DWI defense begins before trial. Recordings can be overwritten, physical evidence lost, and witnesses’ memories weakened.
Counsel may demand body-camera footage, dash-camera footage, dispatch records, warrants, breath-machine records, laboratory data, chromatograms, maintenance logs, medical records, and witness statements. The attorney may inspect the location, subpoena missing evidence, interview passengers, and retain an independent toxicologist.
Pretrial motions can suppress an illegal stop, exclude an unconstitutional search, attack an unreliable scientific opinion, or prevent misleading testimony. A hearing also locks officers and analysts into sworn statements. Contradictions between their testimony, the video, and the report can destroy credibility.
When critical evidence is excluded or exposed as unreliable, prosecutors may be forced to dismiss or reduce the charge. If the State refuses a fair result, the defense must be ready to cross-examine every witness and try the case.
Defending Against a Driver’s License Suspension
A DWI arrest may trigger a separate Administrative License Revocation proceeding. A driver generally has 15 days after being served notice to request a hearing following an alleged refusal or failed specimen test. Missing the deadline can permit suspension without a contested hearing.
At the ALR hearing, counsel may challenge reasonable suspicion, probable cause, the specimen request, the alleged refusal, or the failure. The attorney may question the arresting officer under oath and preserve testimony for the criminal case. When suspension cannot be defeated, counsel can evaluate an occupational driver’s license.
Put your State’s Case on Trial With a Texas DWI Lawyer
A Texas DWI lawyer can challenge the stop, testing, and every weakness in the prosecution’s evidence. Contact Paul F. Tu Attorney at Law today at 713-774-2800 for aggressive DWI defense in Richmond and Fort Bend County.
