More than four decades ago, the First District Court of Appeals, based in Houston, defined an extraneous offense as: “… any act or misconduct, whether resulting in prosecution or not, which is not shown in the charging instrument and which was shown to have been committed by the accused.”


Four articles in the Texas Code of Criminal Procedure primarily deal with the admissibility of evidence of extraneous offenses. They are:


  • Tex. Code Crim. Proc. arts. 37.07 and 37.071: These articles deal with extraneous conduct evidence and the admissibility of such evidence during the punishment of a criminal trial.
  • TexCode Crim. Proc. arts. 38.36 and 38.37: These articles deal with the admissibility of uncharged misconduct in murder and child abuse cases.


Extraneous conduct can be something as simple as unpaid debts or as serious as uncharged criminal conduct. Courts are more inclined to admit the former kind of extraneous evidence than uncharged criminal conduct because it has less prejudicial potential.


Two rules in the Texas Rules of Evidence deal with the admissibility of extraneous evidence as well:


  • Tex. R. Evid. 403: The Court may exclude evidence if its probative value is substantially outweighed by a danger of one or more of the following: unfair prejudice, confusing the issues, misleading the jury, undue delay, or needlessly presenting cumulative evidence.
  • Tex. R. Evid. 404(b): Evidence of a crime, wrong, or other act is not admissible to prove a person’s character in order to show that on a particular occasion, the person acted in accordance with the character.


For example, under Rule 404(b), the courts have held that the State cannot introduce evidence that the defendant had consensual anal sex with his common-law wife to forward the State’s contention that he had anal sex with the children of the common-law wife. The Court found the admission of such evidence in error because the testimony’s purpose was to prove nothing more than the appellant’s character in order to show that he acted in conformity therewith.


As for Rule 403 about extraneous offense evidence, the courts follow the basic premise that if the State has sufficient evidence to prove an issue at trial and if the extraneous evidence is not, either standing alone or in combination with other evidence, not particularly compelling, then it should be excluded because its probative value is substantially outweighed by its unfair prejudice.


It is significant to point out that under the Texas Rules of Evidence, there is a difference between an “extraneous offense” and “prior misconduct.” An extraneous offense is conduct that violates a state or federal penal code, while prior misconduct deals with acts that, while not criminal, are generally considered morally or ethically reprehensible.


In a recent case, a Texas court of appeals upheld a conviction where extraneous offense evidence was used to secure that conviction.


 On February 15, 2024, the Fourteenth District Court of Appeals in Nguyen v. State upheld a felony murder conviction. In that case, the defendant, through counsel, filed a pretrial motion in limine to exclude extraneous offense evidence: colliding with another motorist and evasion from police. Both offenses occurred immediately after the charged felony murder. The Court allowed the extraneous evidence as part of the same charged evidence under the legal theory known as “same transaction contextual evidence.”


On appeal, the defendant argued the extraneous evidence was inadmissible under Rule 404(b); and that even if it was admissible under 404, it should have been excluded under Rule 403 because the evidence’s probative value did not outweigh its prejudicial effect. The appeals court rejected the defendant’s argument under the following premise:


“This sort of [same transaction] contextual evidence refers to those background situations where ‘several crimes are intermixed, or blended with one another, or connected so that they form an indivisible criminal transaction, and full proof by testimony, whether direct or circumstantial, of any one of them cannot be given without showing the others.’ This evidence is deemed admissible because’ events do not occur in a vacuum and . . . the jury has a right to hear what occurred immediately prior to and subsequent to the commission of the act so that they may realistically evaluate the evidence.’ Yet, such evidence must still be ‘necessary to the jury’s understanding of the offense’ such that the charged offense would make little sense without the same transaction evidence.”


38.37 Extraneous Evidence, Sex Crimes Against Children


Evidence of extraneous offense or acts admissible under Article 38.37 of the Texas Code of Criminal Procedure is particularly damaging and challenging to overcome. Essentially, it allows evidence of allegations of unrelated sex crimes against children to be admitted as evidence in a trial against a defendant facing allegations of certain sex crimes for all purposes. The statute allows courts to admit unrelated allegations of certain prior bad acts to be admitted for any bearing the evidence has on all relevant matters, including the character of the defendant and acts performed in conformity with the defendant’s character.  


In October 2022, the Third District Court of Appeals, based in Austin, in Poulis v. State rejected a challenge to the constitutionality of Section 2 of Article 38.37 of the Texas Code of Criminal Procedure that allows the use of extraneous offense evidence in certain sexual offenses involving children. Before such evidence is admitted, the trial court must conduct a hearing outside the presence of the jury to determine whether “the evidence is likely to be admitted at trial will be adequate to support a finding by the jury that the defendant committed the separate offense beyond a reasonable doubt.”


The appeals court rejected Poulis’ specific claim that Section 2 “decimates the presumption of innocence, welcomes evidence known to be unfairly prejudicial, and invites jurors to convict based not on evidence proving the charged conduct, but on the accused’s character and propensity for sexual misconduct.”


Extraneous offense and prior misconduct evidence create what is known as a “propensity inference” of guilt with a jury. This damaging evidence undermines the historical foundation of due process, which states that a criminal defendant should be tried for what he did, not who he is.


Defense counsel must be prepared to do everything possible to keep extraneous evidence out of the trial and, if the evidence is admitted, to do everything possible to minimize its propensity inference before the jury. This includes making a timely request for a limiting instruction instructing the jury to use such evidence only for a limited purpose, even if the skunk is already in the jury box.