Written by attorneys · grounded in primary & secondary sources — see below
A bodily movement that the law treats as involuntary and therefore incapable of serving as the basis for criminal liability. The movement occurs without conscious effort or determination by the actor.
Ralph Richardson drove a city bus through downtown traffic. A sudden violent convulsion forced his foot onto the accelerator and held his leg rigid. The bus surged forward and struck a pedestrian in the crosswalk. Because the leg movement was a convulsion rather than a willed act, the prosecution cannot establish the voluntary act element required for reckless assault.
Renee Rogers operated a tower crane on a high-rise site. Without warning she suffered a violent convulsion that jerked her arms and swung the boom. A steel beam dropped and injured a coworker below. The convulsive movement that caused the boom to swing supplies no voluntary act on which assault liability can rest.
Select any source to read its text and confirm it supports the definition.
No. The statute excludes the convulsive movement itself from the category of voluntary acts. Earlier positioning may be relevant to negligence or regulatory violations, but it does not change the character of the reflexive movement that directly causes harm.
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No. The statute classifies the convulsive movement as non-voluntary regardless of the defendant's prior knowledge. Liability requires that the specific bodily movement producing the harm qualify as voluntary. Knowledge of the condition does not transform the movement itself.
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Yes. The statute lists reflexes and convulsions as non-voluntary. A sudden involuntary jerk caused by an external stimulus such as an alarm falls within the excluded category and cannot supply the actus reus for an offense.
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