“Not Having the Normal Use of Mental or Physical Faculties” in DWI Trials

By Collin County Criminal Defense Lawyer Jeremy Rosenthal


(972) 369-0577

Chapter 49 of the Penal Code defines intoxication for the purposes of a Driving While Intoxicated (DWI) case three different ways.  A person is intoxicated if “they do not have the normal use of their mental faculties; do not have the normal use of their physical faculties; or have a blood alcohol concentration of 0.08 or greater…”

Not Having the Normal Use

Herein lies a classic struggle between prosecutor and defense attorney.  The term “normal use” is usually defined by the judge only to be a “normal non intoxicated person.”  That’s all the clarification a jury gets.  It’s as clear as mud.

What the prosecution will often attempt to do — as early as jury selection — is manipulate the definition of “normal” to make it as slight a burden as possible.  The less drunk they have to prove the defendant is, the better their chance of winning at trial.

Attempts at Changing the Definition of Intoxication at Trial

Prosecutors attempt to morph the phrase “normal use” in one of two ways.  They either paraphrase the definition or they give unrealistic examples.

“Not Normal…”

The first is they try to paraphrase “normal use” and in doing so often leave out the word “use.”  Instead, they say a person is intoxicated if “they are one step past normal,” or “not normal.”  They insist to the jury it is a very strict standard to protect the public and most jurors readily agree.  Until they learn the actual law anyway.

Your lawyer in a DWI trial must make sure the jury understands the actual law, not the paraphrased law.  Many things may not be functioning perfectly but still normally.  A bad knee might hurt — but a person can still walk, drive or even run normally.  An airplane can lose an engine yet still function normally.  These examples show how the word-play lessens what it means to be “intoxicated” under the law.

Difficult to Prove Examples

The second way prosecutors try to demonstrate intoxication is by making examples of simple functions such as slower judgment, someone being more talkative or less talkative because of alcohol.

The issue here isn’t so much of the “loss of normal use.”  The issue is these traits are equally consistent with innocence as they are guilt.  The jury should understand a person using slow judgment might be evidence of intoxication — but standing alone is a great way to convict an innocent person.

In Summation

A DWI Defense lawyer must understand focusing on the facts is unfortunately not enough.  It should be enough to win a case to prove a person only had 2 beers.  You can still lose, though, if the prosecution can convince a jury 1 beer gets you legally “intoxicated.”

*Jeremy Rosenthal is Board Certified in Criminal Law by the Texas Board of Legal Specialization and licensed by the Supreme Court of Texas. Nothing in this article should be considered to be legal advice.  For legal advice, please consult an attorney.

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