Gross Vehicular Manslaughter While Intoxicated – Penal Code § 191.5(a)

California treats DUI‑related fatalities very seriously. Penal Code § 191.5(a) makes it a felony to drive while intoxicated and, through an additional grossly negligent act, cause another person’s death. A conviction can lead to long prison terms, heavy fines, and lifetime consequences.

Legal definition

Section 191.5(a) states that gross vehicular manslaughter while intoxicated is the unlawful killing of a human being without malice aforethought when a person drives a vehicle while violating the DUI sections of the Vehicle Code (e.g., § 23140, 23152 or 23153) and the death is the proximate result of either:

• Committing an unlawful act that is not a felony, with gross negligence, or
  
• Committing a lawful act that might produce death, in an unlawful manner and with gross negligence.

This distinguishes gross vehicular manslaughter (subdivision (a)) from ordinary vehicular manslaughter while intoxicated (subdivision (b)), which involves ordinary negligence.

Elements of the offense (CALCRIM No. 590)

According to jury instruction CALCRIM No. 590, prosecutors must prove four elements beyond a reasonable doubt:

1. Driving while intoxicated – The defendant drove a vehicle while under the influence of alcohol and/or drugs. This includes a BAC of 0.08% or higher, or for drivers under 21, 0.05% or higher.
   
2. An additional act – While driving under the influence, the defendant committed a separate misdemeanor, infraction or lawful act that could cause death. The grossly negligent act must be distinct from the DUI itself.
   
3. Gross negligence – The act was committed with gross negligence, meaning the defendant acted in a reckless way that created a high risk of death or great bodily injury and a reasonable person would have known about the risk. Merely driving under the influence and breaking a traffic law is not enough; courts consider the manner of driving and level of impairment.
   
4. Causation – The defendant’s grossly negligent conduct was a substantial factor causing the victim’s death. The prosecution must show a direct and natural link between the act and the fatality, though other contributing factors may exist.

Penalties under Penal Code § 191.5(a)

Gross vehicular manslaughter while intoxicated is always a felony. The statute prescribes the following punishment:

Because § 191.5(a) is a strike offense, prior or subsequent felony convictions can result in doubled sentences or indeterminate terms.

Defenses to gross vehicular manslaughter while intoxicated

Every case is unique, but common defense strategies include:

1. Not intoxicated – Challenging the assertion that you were under the influence. Defense attorneys may attack the reliability of breath or blood tests, challenge the procedures used to collect samples, or argue that symptoms attributed to impairment were due to fatigue or injury.
   
2. Lack of gross negligence – Demonstrating that your conduct amounted to ordinary negligence rather than gross negligence. Driving errors or infractions, even if careless, do not always meet the high threshold of gross negligence.
   
3. Causation – Arguing that factors other than your conduct caused the fatality. Road conditions, weather, mechanical failures or other drivers may be substantial factors. Accident reconstruction experts can help show that the fatality was not a direct result of your actions.
   
4. Sudden emergency – If you faced a sudden emergency and acted as a reasonable person would under the circumstances, your actions may not be grossly negligent.
   
5. Rights violations – Evidence obtained through unlawful searches, improper traffic stops, or violations of Miranda rights may be suppressed, weakening the prosecution’s case.

Related offenses

California law provides lesser and alternative charges for DUI‑related fatalities:

• Penal Code § 191.5(b) – Vehicular manslaughter while intoxicated, requiring only ordinary negligence. It is a wobbler punishable by up to one year in county jail or 16 months, 2 years or 4 years in prison. Defense counsel often seek to reduce gross manslaughter charges to this lesser offense when gross negligence is not clear.
  
• Penal Code § 192(c) – Vehicular manslaughter (no intoxication requirement). This offense may be charged when there is insufficient evidence of intoxication.
  
• DUI murder (Watson murder) – Under Penal Code § 187, prosecutors may charge second‑degree murder (the “Watson” rule) if a repeat DUI offender, previously admonished about the dangers of impaired driving, causes a fatal crash. When someone is accused of or convicted of a DUI, the judge will often read that admonishment, setting someone up for this charge in case it were to ever happen.
  

How Radford & Rome, LLP can help

Facing a gross vehicular manslaughter while intoxicated charge can be life‑altering. The prosecution must prove that you were under the influence, that you committed an additional act with gross negligence, and that your conduct caused the death. Each of these elements provides opportunities for a skilled defense. Radford & Rome, LLP—comprised of former prosecutors—meticulously investigates DUI‑fatality cases, challenges forensic evidence and police procedures, and works with accident reconstruction experts to build the strongest defense.

If you or someone you know has been arrested under Penal Code § 191.5(a), contact Radford & Rome, LLP for a confidential consultation. Our attorneys will explain your rights, evaluate potential defenses, and fight to achieve the best possible outcome.