Intoxication Assault and Intoxication Manslaughter: When a DWI Becomes a Felony

You had a few drinks and got behind the wheel, thinking you were fine to drive. Then came a crash that hurt or killed someone. In that moment the case stopped being an ordinary DWI. Intoxication assault and intoxication manslaughter are felonies that carry prison time measured in years or decades, and Texas juries take them seriously.

If you or someone you love is facing one of these charges in Collin County, understanding what the State actually has to prove is the place to start.

What Is Intoxication Assault?

Intoxication assault is defined in Texas Penal Code § 49.07. A person commits the offense if, by accident or mistake, they:

• Operate a motor vehicle in a public place while intoxicated, and
• By reason of that intoxication, cause serious bodily injury to another person.

The statute also covers boats, aircraft, and amusement rides, but the cases that reach the Collin County courts are almost always car and truck crashes, so this article talks about driving.

What Counts as “Serious Bodily Injury”?

Under Texas law, serious bodily injury means an injury that creates a substantial risk of death, causes serious permanent disfigurement, or causes protracted loss or impairment of the function of any bodily member or organ. Whether a particular injury qualifies depends on its severity and lasting effects: a traumatic brain injury or the loss of a limb will usually meet the definition, while injuries that heal cleanly may not.

The Penalty for Intoxication Assault

Intoxication assault starts as a third-degree felony: 2 to 10 years in prison and a fine of up to $10,000. The charge is enhanced based on who was injured, under Penal Code § 49.09:

Circumstances	Offense Level	Range
Most cases	Third-degree felony	2 to 10 years
Firefighter or EMS worker on duty	Second-degree felony	2 to 20 years
Traumatic brain injury causing a persistent vegetative state	Second-degree felony	2 to 20 years
Peace officer or judge on duty	First-degree felony	5 to 99 years or life

What Is Intoxication Manslaughter?

Intoxication manslaughter is defined in Texas Penal Code § 49.08. A person commits the offense if they operate a motor vehicle in a public place while intoxicated and, by reason of that intoxication, cause the death of another person by accident or mistake.

The baseline penalty is a second-degree felony: 2 to 20 years in prison and a fine of up to $10,000.

When Intoxication Manslaughter Becomes a First-Degree Felony

A first-degree felony in Texas carries 5 to 99 years or life. Intoxication manslaughter reaches that level in three situations:

1. The person killed was a peace officer, judge, firefighter, or EMS worker in the actual discharge of official duty. This enhancement existed before 2025.
2. More than one person was killed in the same criminal transaction. This is the change made by Senate Bill 745, effective September 1, 2025. Before that date, a multi-death crash was charged as separate second-degree counts, and the court could order the sentences served back to back. Now a single count can carry a life exposure.
3. The driver has a prior conviction for an intoxicated-operating offense and was in violation of Penal Code Chapter 51, Texas’s illegal-entry law, at the time of the offense. This narrower provision comes from House Bill 2017, also effective September 1, 2025. A defendant convicted under this specific provision is not eligible for community supervision and must serve 10 calendar years, without good conduct time counting, before becoming eligible for parole.

Both 2025 laws apply only to offenses committed on or after September 1, 2025. A crash before that date is judged under the old law.

Multiple Victims Mean Multiple Counts

Each injured or deceased person can be charged as a separate count, and Texas law treats intoxication offenses differently from most crimes when it comes to sentencing: under Penal Code § 3.03(b), sentences for intoxication assault and intoxication manslaughter arising from the same crash may be stacked, one after another, rather than run at the same time. A single bad night can produce an effective sentence far longer than any one count suggests.

The Element the State Has to Prove: Causation

Both offenses require the State to prove the injury or death happened “by reason of” the intoxication. It is not enough that a driver was intoxicated and a crash happened. The intoxication has to be a cause of the result in the legal sense.

Texas applies a but-for standard with a wrinkle for concurrent causes: the result must be one that would not have occurred but for the intoxication, operating either alone or together with another cause, and if the other cause was clearly sufficient by itself while the intoxication was clearly insufficient, the element fails. In plain terms, if the crash would have happened exactly the same way to a sober driver, for example because another driver ran a red light in a way no one could have avoided, the causation element may not be met even if the defendant was legally intoxicated. Causation is where many of these cases are actually fought.

There is a civil side to these cases too. A person seriously hurt by an intoxicated driver, or a family that loses someone, may also have a civil claim, depending on the facts, separate from anything the State does in the criminal case. Kent handles that side through Starr Injury Law.

Defending Against These Charges

Every case turns on its own facts, but the defense work in intoxication assault and manslaughter cases usually concentrates in a few places:

1. Causation. As discussed above, the State must prove the intoxication caused the result. Accident reconstruction, road and weather conditions, and the other driver’s conduct all matter.
2. The intoxication evidence itself. Blood draws and breath tests have rules: the legality of the stop and the warrant, the qualifications of the person who drew the blood, the maintenance records of the testing equipment, and the chain of custody. Problems in any of those can change a case.
3. The injury element. For intoxication assault, the State must prove the injury meets the legal definition of serious bodily injury. Not every painful injury does.
4. Charge and punishment negotiation. Depending on the evidence, the realistic goal may be a reduced charge, or it may be careful preparation of the punishment case. An honest assessment early is worth more than bravado.

A word about probation: deferred adjudication is not available for intoxication assault or intoxication manslaughter. (Texas opened deferred adjudication to some first-time DWI cases in 2019, but those two offenses were left out.) Straight probation is possible in limited circumstances, and for intoxication manslaughter it still comes with mandatory county jail time as a condition. Under the 2025 House Bill 2017 provision described above, probation is off the table entirely.

Intoxication Assault and Manslaughter Defense in McKinney and Collin County

Kent Starr has practiced criminal defense in Collin County and across North Texas since 1997, from his office in McKinney, the county seat, where these felonies are presented to the grand jury and tried in the district courts. He is a solo lawyer: the person you talk to at the consultation is the person who reads the crash reconstruction, challenges the blood evidence, and tries the case if it comes to that.

These cases move fast at the start. The State often seeks a blood warrant the night of the crash, and the window for the defense to preserve its own evidence, skid marks, vehicle data, camera footage, witness memories, closes quickly. If you or a family member is facing intoxication assault or intoxication manslaughter charges, talk to a lawyer before you talk to anyone else. The consultation is free and confidential, and Kent takes it himself: (214) 982-1408.

For the wider picture of how a felony case moves through the local courts, see the Collin County criminal defense guide. For when a DWI becomes a felony in other ways, see Is a DWI a felony in Texas? and the 2026 DWI law changes.

References

• Texas Penal Code § 49.07 (Intoxication Assault)
• Texas Penal Code § 49.08 (Intoxication Manslaughter)
• Texas Penal Code § 49.09 (Enhanced Offenses and Penalties)
• Texas Penal Code § 3.03 (Sentences for Offenses Arising Out of Same Criminal Episode)
• Senate Bill 745, 89th Legislature (2025)
• House Bill 2017, 89th Legislature (2025)