Short Answer

Texas Penal Code §6.04(a) says your conduct caused a result if the result wouldn’t have happened but for that conduct, whether it operated alone or together with another cause. That second part matters. A concurrent cause doesn’t get you off the hook by itself. The statute carves out only one exception: when the other cause was clearly sufficient to produce the result on its own and your conduct was clearly insufficient. Section 6.04(b) addresses a different issue. Criminal responsibility remains when the only difference from the result the actor desired, contemplated or risked is that a different offense occurred, or a different person or property was affected. Which rule applies, and whether the facts fit it, has to come out of the medical and factual record.

Why This Question Matters

Causation is its own element, and the State has to prove it beyond a reasonable doubt. Say the autopsy lists a gunshot wound and an untreated heart condition. Section 6.04 decides whether that second cause changes anything, and in a Texas murder case the timeline and the quality of the medical analysis matter as much as the one-line cause of death on the report.

How I Would Analyze the Issue

Start with the medical examiner’s actual findings and the records behind them, not the summary line. Lay them against the timeline. Does the evidence support but-for causation at all? Was a second cause operating at the same time? Could the clearly-sufficient and clearly-insufficient exception apply here? The medical opinion and the statutory test stay separate, because they answer different questions.

What the Prosecution May Try to Establish

The State uses medical testimony to argue your conduct was a but-for cause, alone or alongside another one, and that nothing else severs legal causation. Measure that position against the words of §6.04 and the underlying records, not a summary.

What the Defense Must Test

A medical causation opinion is only as good as its methods and assumptions. Were the records complete? Is there real support for the other possible causes? Then compare the opinion with the but-for and concurrent-cause rules. A medical contribution isn’t automatic legal causation, and a contributing condition doesn’t automatically break the chain. The statute says neither.

Evidence and Documents to Review

• Scene evidence
• Medical findings
• Communications
• Video
• Device and location records
• Witness accounts
• Timelines
• Expert data
• Evidence of other plausible actors or causes

Questions That Can Change the Analysis

• What result does the medical evidence identify, and what records support that conclusion?
• Did another condition or event operate concurrently?
• Does the evidence support but-for causation under §6.04?
• Could the clearly-sufficient/clearly-insufficient exception apply to the facts?

Common Misunderstandings

A second contributing cause doesn’t automatically defeat causation.

Medical causation opinions and the statutory legal test are related, but you can’t swap one for the other.

Section 6.04(a) contains a narrow concurrent-cause exception. It isn’t a rule that any other contributing factor breaks causation.

Local Case Considerations

Where a death investigation happens determines which agencies and which medical examiner’s records are involved. Confirm the court and case number, then find out which records and opinions the State is relying on for cause and manner of death.

What Families Should Preserve

Preserve the medical and autopsy records, photographs, toxicology materials, treatment records and any evidence-handling documentation you can get. Don’t write on the originals or alter them. Note where each copy came from and give them privately to your defense lawyer.

Discuss the Case With Counsel

Counsel may need the underlying records and methods, not just the conclusion, to evaluate the charged theory, since the medical opinion and the legal test are different things. Those records also bear on how intent is proven or disputed (forthcoming article). Call Heath Hyde, P.C. at 903.439.0000 or request a confidential consultation.

Frequently Asked Questions

Does another contributing cause always defeat a murder charge?

No. Section 6.04 generally recognizes concurrent causes. The exception is narrow: the other cause must have been clearly sufficient by itself and the conduct at issue clearly insufficient.

Is medical cause the same as legal cause?

Not necessarily. Medical evidence informs the factual analysis. The statute supplies the legal rule.

Can causation be decided from a short summary?

Usually not. The records, the expert’s methods, the timeline and the charged theory have to be looked at together.

Legal Sources

Texas Penal Code §§6.03–6.04: https://tcss.legis.texas.gov/resources/PE/htm/PE.6.htm

Texas Penal Code §19.02: https://tcss.legis.texas.gov/resources/PE/htm/PE.19.htm