How Evidence Is Used in DWI Cases

If you or a loved one were arrested & charged with a Driving While Intoxicated (DWI) offense in Texas, it can be a daunting experience.

As a seasoned Texas DWI Lawyer, I’m always willing to help people charged with DWI and other crimes in the Greater Houston area. The main aspect of understanding how these cases are prosecuted in court is related to the evidence and how it’s used.

If you’re seeking legal representation following criminal charges for DWI or DUI, my office is here to help. I’m Tad Nelson, a Board Certified® Texas Criminal Law Attorney. If you need to speak with a defense attorney or have questions, call us at 281-280-0100.

DWI Offenses & Texas Law

In Texas, it’s illegal to operate a motor vehicle while intoxicated. Intoxication is defined as having a blood alcohol concentration (BAC) of 0.08% or higher as outlined in Texas Penal Code Section 49.04.

A person can also be charged with this offense if they’re operating a motor vehicle while impaired by legal or illegal drugs.

Evidence in DWI Cases

Evidence plays a big part in the outcomes of DWI cases. The burden of proof rests on the prosecution. This means that the state must present evidence to prove beyond a reasonable doubt that you were operating a vehicle while intoxicated.

Understanding the type of evidence used in court will give you better insights into how we might prepare your defense. If you’re confused or have any questions about DWI evidence, contact Attorney Tad Nelson today at 281-280-0100.

Types of Evidence in DWI Cases

Field Sobriety Tests

Usually, during a DWI stop, officers will conduct field sobriety tests at the scene to assess a driver’s impairment.

These tests usually involve physical and cognitive tasks, such as standing on one foot or walking in a straight line. Although they aren’t always reliable indicators of impairment, the results can be used as evidence or justification for a DWI arrest.

Breath and Blood Tests

In Texas, you’re defined as “per se intoxicated” if your BAC is 0.08% or higher. Breathalyzer & blood tests are commonly used to determine BAC. However, these tests have to be administered under very specific conditions to ensure accuracy.

Any deviation from standard testing procedures could render the results invalid. Especially if you have skilled legal representation from an experienced DWI lawyer that knows what to look for and how to challenge said evidence.

Officer Observations

An officer’s observations and testimony play a significant role in DWI cases. If they noticed signs of intoxication, such as slurred speech, erratic driving, or the smell of alcohol, their statements could be used as evidence.

Although alcohol has no smell, the additives and ingredients are what people and officers smell when they “think” they smell alcohol. The smell of alcohol is not evidence.

Video Evidence

Many police departments now equip their officers with cameras. These cameras may be part of their uniform, vehicle, or both. These cameras provide visual and audio evidence. If your arrest was recorded, the video could be used in court.

Expert Testimony

In some cases, the prosecution may call on expert witnesses, such as forensic toxicologists or accident reconstruction experts. Their job will be to testify about the effects of alcohol or drugs on the human body, or how the incident could have occurred. If there was a car accident resulting in death as a result of DWI, there’s a strong chance an accident reconstruction specialist will be called in to testify should the case go to trial.

Challenging DWI Evidence in Court

Any evidence presented against you in a DWI case is subject to scrutiny. Challenging the validity, reliability, and admissibility of this evidence is how the Law Offices of Tad Nelson & Associates would build a cornerstone of your defense. As an ACS/CHAL Lawyer-Scientist, few traditional criminal defense lawyers in Houston can challenge evidence more effectively than our law offices.

Field Sobriety Tests

Field sobriety tests are highly subjective. Varying factors such as weather conditions, individual physical abilities, or even the type of footwear, can influence the outcomes of these tests. Depending on the circumstance of the situation, our law firm may be able to successfully challenge the administration and interpretation of these tests. If we’re successful, there’s a chance your DWI or DUI case will be dismissed.

Breath and Blood Tests

Inaccuracies in breath or blood tests can result from improper administration, faulty equipment, or the handling and storage of samples. We can question the validity of these tests by analyzing the conditions and procedures under which they were conducted.

Officer Observations

Police officers are human beings. Human beings and prone to making mistakes. They can misinterpret situations or recall incidents inaccurately. Cross-examination of the arresting officer is an effective strategy to challenge these observations.

The observations of the police officers can be used as evidence, making it important to cross-examine and challenge their account of the incident.

Video Evidence

Although video evidence might seem irrefutable to most folks, all evidence is open to interpretation. Inconsistencies between the officer’s report and the actual video, or poor quality of the footage can be points of contention.

Expert Testimony

While expert witnesses might seem intimidating, we always have the option to challenge their credibility, qualifications, or the scientific validity of their claims. This strategy often requires the help of an expert on your side. With the skills and training of Mr. Nelson, a Board Certified® criminal law attorney, and ACS/CHAL lawyer-Scientist, you’ll already have an expert on your side.

Leveraging The Texas Rules of Evidence

The Texas Rules of Evidence provide a framework for what’s considered admissible in court. Understanding these rules is helpful in building a defense strategy.

Rule 401 and Rule 402: Relevant Evidence

According to Rule 401, evidence is considered relevant if it has any tendency to make a fact more or less probable than it would be without the evidence. However, even if the evidence is deemed relevant, it can be excluded under Rule 402 if its probative value is substantially outweighed by the risk of unfair prejudice, confusion, or waste of time.

Rule 403: Excluding Relevant Evidence

Under Rule 403, relevant evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion, misleading the jury, undue delay, or needless presentation of cumulative evidence.

Rule 702: Testimony by Expert Witnesses

Expert testimony is governed by Rule 702. For an expert’s testimony to be accepted, it must be shown that the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue.

The Importance of Legal Representation in DWI Cases

If you were arrested for DWI in the Greater Houston area you don’t have to deal with the situation alone. Houston DWI Lawyer Tad A. Nelson will help you understand legal procedures, rules of evidence, and strategies we might use in court to keep you free of a criminal record.

Your freedom, your reputation, and your future may very well hinge on how the evidence in your DWI case is handled in court. And that’s where the assistance of an experienced attorney like Tad Nelson can prove invaluable.

Since 1991, Attorney Tad Nelson has helped thousands of Houstonians and other Texans to avoid DWI convictions.

Arrested on Suspicion of DWI?

Contact Attorney Tad Nelson & Associates today!

Tad Nelson is Board Certified in Criminal Law by the Texas Board of Legal Specialization and ACS/CHAL Lawyer-Scientist. Very few defense lawyers in Texas are capable of defending people suspected of DWI to the degree that we can.

If you have any questions, contact us today at 281-280-0100.