How a Manslaughter Lawyer Tests Criminal Negligence and Causation

The alleged predicate offense may be a misdemeanor, infraction, or, under recognized case law, a felony that is not inherently dangerous. The prosecution must identify the predicate offense and establish its elements. Alternatively, otherwise lawful conduct may support a charge when performed with criminal negligence. A tragic outcome does not establish that either theory applies. For a broader overview of the offense, see involuntary manslaughter.

CALCRIM No. 582 requires proof that the defendant owed a legal duty to the deceased, failed to perform it, acted with criminal negligence, and caused the death. A parent or paid caretaker may owe duties that an unrelated bystander does not. The judge determines whether the law recognizes a duty, although disputed facts that would establish it may require a jury finding. Care agreements, witness accounts, and evidence of assumed responsibility can be decisive.

A mistaken judgment may amount to ordinary negligence without establishing criminal negligence. Prosecutors must show more than a preventable accident. The assessment considers the danger apparent before the event, not merely the seriousness of the injury afterward. Unlike implied-malice murder, this offense does not require proof that the defendant personally recognized a risk to life and consciously disregarded it.

Prior safety complaints, inspection reports, training materials, and equipment logs can reveal whether a serious hazard was recognizable. Records identifying who controlled a site or authorized the activity may clarify the defendant's role. A policy violation is relevant evidence, but it does not itself prove the required level of criminal negligence. Conversely, a sudden equipment failure or an unreported defect may alter what a reasonable person could have anticipated.

Autopsy findings can identify injuries and a medical cause of death, while treatment notes show how the patient's condition changed. Toxicology results may identify substances that contributed to the outcome. Investigators should compare those findings with the incident timeline and witness descriptions. A death certificate alone does not settle whether the defendant's particular conduct caused the death in the legal sense. Contradictions warrant closer review of the criminal evidence.

CALCRIM No. 620 recognizes that several events can contribute to one death. A victim's underlying illness or another person's carelessness does not eliminate responsibility if the defendant's conduct was a substantial factor. Ordinary medical negligence does not erase causation if the original injury remains a substantial factor. Grossly improper treatment may change the result if the original injury was not a substantial factor and the treatment caused death.

Surveillance video, photographs, text messages, inspection records, emergency calls, and witness statements can place decisions in sequence. Preserve original files and available metadata, including collection dates and source information. Proper evidence preservation helps prevent routine deletion without altering or selectively editing records.

A forensic pathologist may assess injury patterns and alternative medical explanations. A reconstruction specialist may examine physical conditions or the feasibility of competing timelines. Independent analysis should test the methods, source data, and assumptions behind the prosecution's conclusion. An expert may also identify where timing estimates exceed the limits of the available records.