The defense strategy in a Texas DWI case depends on the facts and evidence, but three of the most common are to challenge the legality of the traffic stop, question whether there was probable cause for the arrest, and argue that the state’s evidence fails to prove intoxication.
Was There a Lawful Basis for the Traffic Stop?
A defense attorney can examine the reason the officer gave for stopping the vehicle and compare it with reports, dash-camera or body-camera video, dispatch records, traffic evidence, and other available information. A traffic stop generally requires a lawful constitutional basis, such as reasonable suspicion supported by specific facts or another recognized justification.
Reasonable suspicion means the officer has specific facts that reasonably suggest a traffic violation or other unlawful conduct may be occurring. Examples can include observing a vehicle speeding, failing to signal a turn, crossing a marked lane, running a stop sign, or displaying driving behavior that reasonably suggests impairment.
When evidence was obtained as a result of an unlawful stop or other unlawful police conduct, the defense may file a motion to suppress. A motion to suppress asks the court to exclude evidence from being used against the defendant. If the court finds that evidence was obtained unlawfully and suppression is legally required, excluding that evidence can reduce the proof available to the prosecution.
Was There Probable Cause for the Arrest?
A lawful traffic stop does not by itself establish probable cause for a DWI arrest. Probable cause requires facts and circumstances that would lead a reasonable person to believe that an offense has been committed. A defense attorney can examine what the officer observed and knew before making the arrest, including driving behavior, physical observations, statements, field sobriety test performance, video, and available breath or blood evidence.
The strategy is to determine whether those facts, considered together, actually support the arrest. If the evidence is inconsistent, incomplete, or has an innocent explanation, the defense may challenge whether probable cause existed for the arrest and whether evidence obtained after the arrest should be excluded.
Does the Evidence Prove Intoxication?
The prosecution must prove intoxication as Texas law defines it. If the state relies on an alleged loss of normal mental or physical faculties, the defense can compare officer observations with video, witness testimony, medical information, field sobriety evidence, and other evidence to show that the person did not lose the normal use of those faculties because of alcohol or drugs.
If the state relies on a breath or blood result, the defense can examine whether the specimen was legally obtained and whether the reported result was produced through a legally and properly conducted testing process. When the law provides a basis for suppression, the defense may ask the court to exclude the test result. Even when the test remains admissible, the defense can compare the reported result with the other evidence and argue that the state’s evidence as a whole does not establish intoxication beyond a reasonable doubt.
