In Texas, extraneous offenses are crimes or bad acts a defendant is not currently charged with, and prosecutors can introduce them at trial only under specific rules that differ between the guilt phase and sentencing. During guilt-innocence, Texas Rule of Evidence 404(b) generally bars this evidence when offered to show character, but allows it for other purposes like intent, motive, or identity. At sentencing, the door opens much wider. Sexual offense cases follow their own set of rules under Article 38.37, and every stage carries notice, balancing, and proof requirements the defense can invoke.
What an Extraneous Offense Is
An extraneous offense is any crime, wrong, or bad act outside the conduct the defendant is on trial for. It might be a prior conviction, an arrest that never produced charges, or behavior that no one ever reported to police. The defining feature is that the jury would not otherwise hear about it based on the charged offense alone. Texas courts treat these allegations carefully because of an obvious risk: jurors who learn a defendant has done bad things before may convict based on character rather than on the evidence for the charge in front of them.
The General Rule Against Character Evidence
Texas Rule of Evidence 404(b) sets the baseline. It prohibits using evidence of other crimes or bad acts to show that the defendant has a certain character and acted consistently with it. In plain terms, the state cannot introduce a prior theft to argue “this person is a thief, so they probably committed this theft too.”
The rule allows extraneous offense evidence when it serves a purpose other than character conformity. The Texas Court of Criminal Appeals explained the framework in Montgomery v. State (1991), holding that extraneous offense evidence is admissible when it makes an element of the charged crime or a defensive theory more or less likely, independent of any character inference.1Justia Law. Montgomery v. State Recognized non-character purposes include motive, opportunity, intent, preparation, plan, knowledge, identity, and absence of mistake. In Robbins v. State (2002), the court upheld admission of evidence showing previous injuries a victim suffered while in the defendant’s care, finding it relevant to intent and the absence of accident.2Justia Law. Robbins v. State
Courts scrutinize the stated purpose. Labeling evidence as “proof of intent” is not enough if intent is not actually in dispute. The more specific and genuinely contested the issue, the stronger the case for admission.
The Rule 403 Balancing Test
Passing the relevance test is only the first step. Texas Rule of Evidence 403 allows a judge to exclude relevant evidence when its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury. Most extraneous offense fights are decided here.
Under Montgomery, once evidence clears Rule 404(b), a presumption favors admissibility, and the opponent must show that prejudice substantially outweighs usefulness.1Justia Law. Montgomery v. State The court identified several factors: how much the prosecution needs the evidence, whether other proof of the same point exists, how strong the link is between the extraneous act and the charged offense, and how likely the evidence is to inflame the jury.
Timing matters. An extraneous act from decades ago with no connection to the current charge is far less likely to survive Rule 403 than a recent, similar act that forms part of an ongoing pattern. When the state has other strong evidence on the same point, the extraneous offense carries less weight in the balance and becomes more vulnerable to exclusion.
Same-Transaction Contextual Evidence
Texas treats one category of extraneous evidence outside the usual 404(b) analysis. When uncharged conduct is so intertwined with the charged offense that the jury cannot understand the crime without hearing about it, courts may admit it as same-transaction contextual evidence. A drug deal that turns into a shooting is a common example: the jury often needs the drug transaction to make sense of what came next.
This evidence does not have to fit one of the 404(b) permitted purposes. Rule 404(b) itself recognizes the category by excluding evidence “arising in the same transaction” from its notice requirements. The evidence still has to survive Rule 403 balancing, and the trial court can limit how much contextual detail the jury hears.
Sexual Offense Cases Under Article 38.37
Texas law carves out a significant exception to the ban on character-conformity evidence in cases involving sexual offenses. Article 38.37 of the Code of Criminal Procedure has two sections that expand what prosecutors can introduce, and both go further than Rule 404(b) allows elsewhere.
Section 1 applies to a broad list of sexual offenses and trafficking crimes. In those prosecutions, evidence of other crimes committed by the defendant against the same victim is admissible to show the state of mind of both the defendant and the victim and to illustrate their prior relationship.3State of Texas. Texas Code of Criminal Procedure Article 38-37 Section 1 The prior acts must involve the same victim.
Section 2 is the true propensity exception. In prosecutions for specific child sexual abuse offenses, including continuous sexual abuse of a child, indecency with a child, sexual assault of a child, and several related crimes, the state can introduce evidence that the defendant committed other similar offenses against any victim. That evidence can be used “for any bearing the evidence has on relevant matters, including the character of the defendant and acts performed in conformity with the character of the defendant.”4State of Texas. Texas Code of Criminal Procedure Art. 38.37 – Evidence of Extraneous Offenses or Acts The exact reasoning Rule 404(b) prohibits in other cases is expressly permitted here.
Section 2 carries procedural safeguards. Before the evidence reaches the jury, the trial judge must hold a hearing outside the jury’s presence and determine that the evidence is sufficient to support a finding beyond a reasonable doubt that the defendant committed the separate offense. The prosecution must also give the defense at least 30 days’ notice before trial of its intent to offer Section 1 or Section 2 evidence.4State of Texas. Texas Code of Criminal Procedure Art. 38.37 – Evidence of Extraneous Offenses or Acts
Extraneous Offenses at Sentencing
The rules loosen considerably during the punishment phase. Under Article 37.07, Section 3(a)(1) of the Code of Criminal Procedure, the state may introduce evidence of any extraneous crime or bad act relevant to sentencing, regardless of whether the defendant was ever charged with or convicted of that conduct.5State of Texas. Texas Code of Criminal Procedure Chapter 37 – Verdict Prosecutors get broad latitude to paint a picture of the defendant’s overall conduct and character when the sentence is decided.
The standard of proof at this stage is beyond a reasonable doubt, not preponderance of the evidence. The statute requires that extraneous misconduct be “shown beyond a reasonable doubt by evidence to have been committed by the defendant.”5State of Texas. Texas Code of Criminal Procedure Chapter 37 – Verdict In Smith v. State (2007), the Court of Criminal Appeals reversed a sentence where the trial judge relied on extraneous misconduct from a pre-sentence report without a sufficient evidentiary basis, holding that due process forbids a court from considering extraneous misconduct when the record provides no rational basis to conclude the defendant was responsible for it.6Justia Law. Smith v. State
Notice Requirements
Prosecutors cannot ambush the defense with extraneous offense evidence. Two notice obligations apply, depending on when and how the evidence will be used.
For evidence introduced during the guilt-or-innocence phase under Rule 404(b), the state must give reasonable advance notice of its intent to offer the evidence in its case-in-chief. This obligation kicks in only when the defense makes a timely request. In Buchanan v. State (1995), the Court of Criminal Appeals held that an “open file” policy does not satisfy the requirement. Making evidence available in the prosecutor’s file is not the same as affirmatively communicating an intent to introduce it at trial.7Justia Law. Buchanan v. State
For punishment-phase evidence, Article 37.07, Section 3(g) requires notice in the same manner as Rule 404(b) when the defense makes a timely request. If the extraneous offense did not result in a final conviction or probated sentence, the notice must include the date, the county where the alleged offense occurred, and the name of the alleged victim.5State of Texas. Texas Code of Criminal Procedure Chapter 37 – Verdict
In Hernandez v. State (2005), the Court of Criminal Appeals confirmed that Rule 404(b) notice is a condition of admissibility, not a suggestion. Admitting extraneous offense evidence without proper notice is error. The court still applied a harm analysis and found no reversible error in that case because the defense suffered no actual prejudice from the missing notice.8Justia Law. Hernandez v. State For Article 38.37 cases, the state must give the defense at least 30 days’ notice before trial.4State of Texas. Texas Code of Criminal Procedure Art. 38.37 – Evidence of Extraneous Offenses or Acts File notice requests early and in writing. Courts have excused deficient notice when the defense had actual knowledge of the evidence.
Limiting Instructions
When a court admits extraneous offense evidence for a limited purpose, the defense can request a limiting instruction telling the jury to consider the evidence only for that purpose and not as proof that the defendant is the type of person who commits crimes. Under Texas Rule of Evidence 105, the court must give the instruction on request. Failing to ask waives the issue on appeal.
Article 38.37 has its own, more protective instruction requirement. When evidence comes in under Section 1 or Section 2, the court must give a limiting instruction both orally at the time the evidence is admitted and in writing when jury instructions are delivered at the end of the case. Either party can request it.3State of Texas. Texas Code of Criminal Procedure Article 38-37 Section 1
Standard of Proof
The threshold for admission depends on the phase. During guilt-innocence, the trial judge acts as gatekeeper and must determine that a jury could reasonably find the extraneous act occurred. In Harrell v. State (1994), the Court of Criminal Appeals addressed this threshold and recognized that, given the potential for unfair prejudice, courts have traditionally imposed a higher bar for this type of evidence than for evidence generally.9Justia Law. Harrell v. State, 884 S.W.2d 154
During punishment, Article 37.07 sets the standard explicitly at beyond a reasonable doubt. The state has to prove to that level that the defendant committed or bore criminal responsibility for the extraneous act before the judge or jury can consider it in sentencing.5State of Texas. Texas Code of Criminal Procedure Chapter 37 – Verdict If the only evidence of an extraneous offense is thin or speculative, challenging its sufficiency can keep it away from the jury entirely.
Preserving Objections for Appeal
Appellate courts review a trial court’s decision to admit or exclude extraneous offense evidence under the abuse-of-discretion standard. The appellate court will not substitute its own judgment. It will reverse only when the trial court acted outside the bounds of reasonable disagreement.
When error is found, the appellate court conducts a harm analysis. For constitutional errors, the reviewing court must determine beyond a reasonable doubt that the error did not contribute to the conviction or punishment. For non-constitutional errors, the question is whether the error had a substantial and injurious effect on the verdict. The analysis considers the strength of the remaining evidence, whether the state emphasized the improperly admitted evidence, and how likely the error was to have influenced deliberations.
None of this matters if the issue is not preserved. If the defense does not object when the evidence is offered, the error is waived. The same goes for limiting instructions: failing to request one forfeits the right to complain on appeal that the jury used the evidence for an improper purpose. When extraneous offenses are likely in a case, build the appellate record from the start, with specific objections under both Rule 404(b) and Rule 403 and a request for a limiting instruction at every opportunity.