CROSSOVER: Childhood Family-Violence Evidence Needs a Rule 702 Fit: Chavez Requires a Case-Specific Nexus to the Claimed Defensive Conduct
Chavez v. State, 14-25-00306-CR, September 22, 2026.
On appeal from 263rd District Court, Harris County, Texas
Synopsis
Rule 702 requires a case-specific nexus between psychological expert testimony and the defensive conduct the testimony is offered to explain. General evidence of a defendant’s mental condition or childhood exposure to family violence does not assist the factfinder in evaluating self-defense when the expert does not connect that history to the complainant or to the defendant’s asserted belief that deadly force was immediately necessary.
Relevance to Family Law
Although Chavez is a criminal case, its Rule 702 analysis has direct implications for Texas divorce and SAPCR litigation involving family violence, trauma, mental health, and parental decision-making. A party cannot establish admissibility merely by showing that a psychologist is qualified or that childhood trauma may affect adult behavior in the abstract. The proponent must connect the expert’s methodology and opinions to a disputed issue the court must decide—such as whether family violence occurred, whether conservatorship restrictions are necessary, whether a parent presents a current risk to a child, or whether trauma bears on a party’s perception and conduct during a specific incident.
The opinion also highlights an important distinction between contextual evidence and expert evidence. A party may have admissible evidence of family violence or trauma, but an expert must still explain how that history bears on the particular conduct, perception, or risk assessment at issue. Without that analytical bridge, the testimony may amount to generalized background information rather than evidence that will assist the factfinder.
Case Summary
Fact Summary
Isaiah Chavez was charged with murder after shooting Justin Davidson in the back of the head while the two men were seated in Davidson’s truck. The evidence showed that Chavez, Davidson, and others had traveled to a Houston apartment complex in connection with a planned drug transaction. Davidson was known to carry a firearm, and on the day of the shooting his gun remained tucked into the front waistband of his pants.
Chavez admitted that he shot Davidson. He testified, however, that he believed Davidson was going to kill him and that he could not safely leave the truck because Davidson would shoot him if he moved. Chavez saw another gun in the passenger-side door, took it, and fired while Davidson was turned away and looking toward the window or at his phone.
Other evidence complicated the self-defense theory. Security footage did not show an argument, physical struggle, or third person approaching or entering the truck. Chavez admitted that Davidson was turned away when he fired, that Davidson had not removed the firearm from his waistband, and that Chavez waited until Davidson was facing away before shooting. Afterward, Chavez took Davidson’s phone and the gun used in the shooting, left the scene, did not call 9-1-1, and initially told others that another person had shot Davidson.
The trial court nevertheless submitted self-defense to the jury under Texas Penal Code § 9.32. To support that defense, Chavez sought to call clinical psychologist Dr. Anna Buckingham during guilt-innocence. He proposed to offer her opinions concerning his mental condition at the time of the shooting and his childhood exposure to family violence. Chavez did not assert insanity or diminished capacity.
The State objected to the expert testimony, and the trial court excluded it during guilt-innocence. The jury convicted Chavez of murder, and the trial court assessed punishment at 38 years’ imprisonment.
Issues Decided
For the Rule 702 and family-law crossover issue, the Fourteenth Court of Appeals decided:
- Whether Code of Criminal Procedure article 38.36(b) authorized expert testimony concerning Chavez’s mental condition and childhood exposure to family violence in support of self-defense.
- Whether the proposed psychological testimony was sufficiently relevant and helpful under Texas Rule of Evidence 702.
- Whether the expert testimony had an adequate nexus to Chavez’s asserted belief that deadly force against Davidson was immediately necessary under Penal Code § 9.32.
- Whether the trial court abused its discretion by excluding the testimony during guilt-innocence.
Rules Applied
Texas Rule of Evidence 702 permits a qualified expert to offer opinion testimony when the expert’s scientific, technical, or specialized knowledge will help the factfinder understand the evidence or determine a fact in issue. Qualification alone is insufficient. The proponent must establish that the testimony is reliable and relevant to the issue the factfinder must resolve.
Under Tillman v. State, 354 S.W.3d 425, 435 (Tex. Crim. App. 2011), an appellate court reviews the admission or exclusion of expert testimony for abuse of discretion. The ruling must be upheld if it falls within the zone of reasonable disagreement.
Texas Penal Code § 9.32 governs the use of deadly force in self-defense. As relevant here, the defensive issue concerned whether Chavez reasonably believed deadly force was immediately necessary.
Code of Criminal Procedure article 38.36(b) allows certain evidence concerning family violence when a defendant prosecuted for murder raises a justification defense. Its application, however, depends on relevant facts and circumstances concerning family violence committed by the deceased against the defendant. It does not create a general vehicle for admitting evidence of family violence inflicted by other people during other periods of the defendant’s life.
The court construed article 38.36(b) according to its text. Because the statute addresses family violence committed by the deceased against the defendant, it did not authorize expert testimony based merely on Chavez’s childhood exposure to family violence unconnected to Davidson.
Application
Chavez’s self-defense claim turned on his perception that Davidson presented an immediate threat of deadly force inside the truck. The proposed expert testimony therefore needed to assist the jury in evaluating that specific perception and the resulting decision to shoot Davidson.
The proffer did not establish the required connection. Dr. Buckingham’s proposed testimony addressed Chavez’s general mental condition and family violence he may have experienced in his early years. But the evidence did not show that Davidson had committed family violence against Chavez, and the proposed testimony did not otherwise connect Chavez’s childhood experiences to Davidson, the encounter in the truck, or the circumstances Chavez claimed caused him to perceive an immediate deadly threat.
Article 38.36(b) did not cure that defect. The statute is not a broad authorization for any trauma-related expert testimony whenever a murder defendant raises self-defense. Its family-violence provision concerns violence committed by the deceased against the defendant. Because the childhood family violence at issue was not attributed to Davidson, the statutory predicate was absent.
Rule 702 independently required the testimony to help the jury resolve a fact in issue. General psychological history, without an explanation tying that history to Chavez’s perception of Davidson or to the claimed need for immediate deadly force, did not supply the necessary fit. The trial court could reasonably conclude that the testimony would not assist the jury in deciding self-defense.
Holding
The Fourteenth Court held that article 38.36(b) did not authorize the proposed testimony merely because Chavez had raised self-defense. The statute’s family-violence provision applies to relevant family violence committed by the deceased against the defendant, not unrelated childhood family violence.
The court also held that the trial court acted within its discretion under Rule 702. Testimony about Chavez’s general mental condition and childhood exposure to family violence lacked a sufficient nexus to Davidson and to Chavez’s asserted belief that deadly force was immediately necessary.
Accordingly, the exclusion of Dr. Buckingham’s testimony during guilt-innocence was not outside the zone of reasonable disagreement. The court affirmed the murder conviction.
Practical Application
For Texas family-law litigators, Chavez is a useful “fit” case. The criminal statute discussed in the opinion does not govern civil family cases, but Rule 702’s requirement that an expert opinion assist the factfinder applies across Texas litigation. In civil cases, counsel should also frame the analysis through the applicable Robinson and Gammill reliability standards.
In a conservatorship dispute, a psychologist’s discussion of a parent’s childhood trauma should not stop at diagnosis or history. The expert should identify how that history, using an appropriate methodology and adequate case-specific information, bears on present parenting behavior, the child’s emotional or physical welfare, or the need for a particular conservatorship condition. A diagnosis is not a substitute for a best-interest analysis.
When family violence is alleged, counsel should identify the precise proposition for which expert testimony is offered. An expert may be able to explain trauma responses, delayed reporting, recantation, risk factors, or the effect of violence on a child. But the expert must connect the specialized knowledge to the evidence and disputed issue without simply supplying a generalized profile or telling the court whom to believe.
In protective-order litigation, immediacy and future risk often matter. An expert addressing danger or trauma should identify the incidents evaluated, the sources reviewed, the risk-assessment method used, and how the facts inform the statutory findings the court must make. A broad statement that trauma can affect perception or behavior may be accurate but still fail Rule 702’s helpfulness requirement.
The same principle applies to property disputes involving duress, coercion, or impaired decision-making. If psychological testimony is offered to challenge a marital agreement, settlement, transfer, or financial transaction, the expert should connect the relevant condition to the party’s capacity or volition at the time of that transaction. A remote history of trauma, standing alone, does not establish that a particular agreement resulted from duress or that a particular transaction should be set aside.
Finally, the required nexus must appear in the record. Counsel should not assume the court will infer the analytical connection from an expert’s credentials, diagnosis, or report. Use the report, deposition, and Rule 702 hearing to develop the link expressly.
Checklists
Establish the Rule 702 Fit
- Identify the exact disputed fact or statutory determination the opinion will assist.
- Tie the opinion to a specific incident, parenting decision, transaction, or claimed risk.
- Ask the expert to explain each step between the underlying data and the ultimate opinion.
- Establish why specialized knowledge is necessary rather than merely helpful as background.
- Separate general clinical principles from the expert’s case-specific application.
- Confirm that the opinion does not rest solely on the retaining party’s unverified narrative.
- Address reasonable alternative explanations and contrary evidence.
Prepare the Expert Report
- State the precise questions the expert was retained to address.
- Identify all records, interviews, testing, observations, and collateral sources considered.
- Distinguish diagnosis from functional impact and litigation-specific conclusions.
- Explain how any history of family violence or trauma bears on current conduct or risk.
- Connect each material conclusion to facts in the record.
- Describe the methodology used and its accepted application.
- Identify limitations, missing information, and the effect of those limitations.
- Avoid opinions that simply adopt a party’s legal theory or credibility assessment.
Build the Family-Violence Nexus
- Identify the alleged perpetrator and the relationship relevant to the proceeding.
- Establish when, where, and under what circumstances the alleged violence occurred.
- Determine whether the expert is evaluating past effects, current risk, or both.
- Connect the violence to the child, parent, household, or decision presently before the court.
- Explain how remoteness in time affects the expert’s analysis.
- Distinguish violence involved in the current case from unrelated childhood or third-party trauma.
- Match the testimony to the relevant Family Code finding or requested protective measure.
Defend Against a Rule 702 Challenge
- Prepare the expert to articulate the opinion’s relevance in one concise statement.
- Obtain case-specific testimony rather than relying exclusively on general research.
- Develop the methodology and application separately.
- Make a complete offer of proof if the court excludes the testimony.
- Include the expert’s report, qualifications, methodology, and proposed opinions in the record.
- Explain how exclusion affects a material issue in the case.
- Request clear rulings on qualification, reliability, relevance, and permissible scope.
Challenge an Expert Who Lacks Fit
- Require the proponent to identify the specific issue the testimony will help decide.
- Compare the expert’s assumptions with the evidence actually in the record.
- Test whether the opinion concerns the relevant parent, child, incident, or transaction.
- Examine whether the expert has moved impermissibly from general literature to a case-specific conclusion.
- Identify analytical gaps between trauma history and the conduct at issue.
- Distinguish a clinical diagnosis from an opinion concerning parenting ability or legal responsibility.
- Seek limitation rather than total exclusion when only part of the testimony lacks fit.
- Obtain a ruling outside the factfinder’s presence when appropriate.
Preserve the Appellate Record
- Obtain a definitive ruling on the Rule 702 objection.
- State each ground for admission or exclusion with specificity.
- Make an offer of proof through questions and answers or a detailed written proffer.
- Include excluded reports and exhibits in the appellate record.
- Identify the statutory issue the testimony was intended to address.
- Preserve complaints concerning both reliability and relevance.
- Secure findings or clarifying rulings when the basis for exclusion is uncertain.
Citation
Chavez v. State, No. 14-25-00306-CR, slip op. (Tex. App.—Houston [14th Dist.] Sept. 22, 2026, no pet. h.) (mem. op.).
Full Opinion
Family Law Crossover
The crossover mechanism is a Rule 702 gatekeeping determination directed to the relationship between the proposed expert opinion and the issue the factfinder must decide. The court evaluates not only whether the witness is qualified and the subject matter is generally reliable, but also whether the expert’s specialized knowledge fits the particular facts and will assist in resolving a material issue. A separate statute may expand the categories of relevant evidence in a particular proceeding, but it does not eliminate Rule 702’s requirement of a case-specific analytical connection.
In a Texas family-law matter, the issue may arise through a pretrial motion to exclude, a motion in limine followed by a trial objection, or a voir dire examination of the expert outside the factfinder’s presence. The proponent should establish the expert’s qualifications, data, methodology, and application to the disputed family-law issue. The opponent may challenge the analytical gap between a general proposition—such as the effects of childhood trauma—and the requested finding concerning conservatorship, possession, family violence, child safety, capacity, duress, or property rights.
Chavez therefore supports a disciplined approach to trauma and family-violence evidence. The relevant question is not simply whether the history occurred or whether trauma can affect behavior. The Rule 702 question is whether the expert has reliably explained how that history informs the particular perception, conduct, risk, or legal determination presented in the pending case.
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