Involuntary Manslaughter in California (Penal Code § 192(b))

In California, not every homicide involves intent to kill. Under Penal Code § 192(b), involuntary manslaughter is the unlawful killing of another person without malice, typically caused by negligent or reckless behavior during a lawful or unlawful act.

What separates involuntary manslaughter from murder is the absence of intent. But that doesn’t mean prosecutors treat it lightly. A conviction still results in a felony record, prison time, and life-altering consequences. If you’re under investigation or already charged, the facts matter—and so does your defense.

At David P. Shapiro Criminal Defense Attorneys, we defend clients facing the full weight of the state in serious homicide cases. We understand what’s at stake, and we know how to challenge the assumptions that lead to these charges.

Involuntary Manslaughter Under California Penal Code § 192(b)

Involuntary manslaughter is defined as:

“The unlawful killing of a human being without malice… in the commission of an unlawful act, not amounting to a felony; or in the commission of a lawful act which might produce death, in an unlawful manner, or without due caution and circumspection.”

This charge applies when someone causes another person’s death through criminal negligence, or through a non-felony unlawful act, such as a misdemeanor or infraction.

What the Law Excludes

Penal Code § 192(b) specifically excludes deaths caused by the operation of a motor vehicle. Vehicular homicides are charged separately under PC § 192(c).

Examples of Involuntary Manslaughter

• A caregiver improperly administers medication, leading to a fatal overdose
• A contractor ignores safety procedures, causing a structural collapse
• A person handles a weapon recklessly, resulting in an unintended discharge
• An individual gets into a fight and pushes someone, who fatally strikes their head during the fall

In each case, prosecutors will argue that the defendant acted without malice, but with a degree of recklessness that supports criminal liability.

When Negligence Becomes Criminal Under California Law

To convict someone of involuntary manslaughter, the prosecution must prove more than a mistake or accident. They must show criminal negligence, which involves:

• Conduct that creates a high risk of death or serious bodily injury
• A gross deviation from how a reasonable person would act
• Behavior that demonstrates disregard for human life

This is a higher threshold than ordinary negligence, but lower than the malice required for murder.

Penalties for Involuntary Manslaughter in California

Involuntary manslaughter is a felony and carries significant penalties:

• 2, 3, or 4 years in state prison
• Felony probation in certain cases
• A strike on your record if charged alongside another qualifying offense
• Loss of professional licenses or employment opportunities
• Immigration consequences for non-citizens

In addition, if a firearm was used during the commission of the negligent act, prosecutors may add weapons enhancements that increase prison exposure.

Civil Liability and Other Consequences

A conviction for involuntary manslaughter may also open the door to civil wrongful death lawsuits, where surviving family members seek financial damages. This is separate from any criminal sentence.

In professional contexts—healthcare, security, construction, education—a conviction can lead to licensing consequences, loss of certifications, and long-term professional disqualification.

Legal Defenses to Involuntary Manslaughter

We focus on the prosecution’s weakest link—whether that’s their understanding of the law, their evidence, or their theory of what happened. Common defenses include:

1. The Act Was Not Criminally Negligent

The behavior may have been a mistake, but not to the level of criminal negligence. Ordinary carelessness does not meet the legal standard.

2. The Death Was Caused by an Independent Event

Intervening factors—such as another person’s conduct, an unforeseeable medical complication, or the alleged victim’s own actions—may break the chain of legal causation.

3. The Act Was Lawful and Conducted With Reasonable Care

If you were engaged in a lawful activity and took reasonable safety precautions, the charge may not stand.

4. Insufficient Evidence

Many involuntary manslaughter cases are based on assumptions, unclear timelines, or unqualified expert analysis. We challenge the quality of the investigation, the credibility of witnesses, and the admissibility of key evidence.

What Prosecutors Must Prove

To secure a conviction under Penal Code § 192(b), the state must establish:

1. A human being was killed
2. The defendant committed an unlawful act (not a felony), or a lawful act in an unlawful manner
3. The defendant acted with criminal negligence
4. The defendant’s conduct caused the death

Each of these elements is vulnerable to challenge when the defense is properly prepared.

Why Early Legal Action Matters

Involuntary manslaughter cases often begin as investigations. You may not be arrested immediately. Law enforcement may ask for statements, search your devices or home, or send subpoenas. Saying the wrong thing—or waiting too long—can limit your options later.

Early intervention by a defense attorney allows you to:

• Protect yourself from self-incrimination
• Begin gathering evidence while it’s still fresh
• Engage with investigators before charges are filed
• Build a proactive defense that pressures the prosecution to re-evaluate

Our Approach to Involuntary Manslaughter Defense

We treat every case as if it could go to trial. That means:

• Independent expert analysis of medical, forensic, or mechanical evidence
• Early witness interviews and cross-referencing of reports
• Comprehensive timeline development to clarify cause and effect
• Focused pressure on the DA’s office from the moment we’re retained

Because involuntary manslaughter charges are about what should have been done, we show what the law actually requires—and where reasonable people can disagree.

If you’ve been accused under Penal Code § 192(b), your defense starts now. Not when charges are filed. Not at arraignment. Now.

Contact Our San Diego Criminal Defense Attorney Today

If you or someone you love is facing criminal charges in California, swift action is imperative. The penalties can be life altering and long lasting. Give us a call today to set up a case evaluation with one of our attorneys and learn how to best protect your freedom and future.

Too often, we see clients who “wait and see,” unsure of the legal landscape ahead, only for charges to escalate. They then find themselves backpedaling into a bad defense and an even worse lawyer. Don’t let that happen to you. Protect your freedom. Protect your future. Know your rights.

The contents of this article and blog are meant for informational and marketing purposes only and do not constitute legal advice. Viewing and/or use of the blog does not form an attorney-client relationship. No statements in this post are a guarantee, warranty, or prediction of a particular result in your case.