Also known as: accidental killings · accidentally kill · accidentally killed · accidentally killing · unintentional killing
Written by attorneys · grounded in primary & secondary sources — see below
A form of homicide resulting from a lawful act performed in a lawful manner under a reasonable belief that no harm could occur.
Austin Abbott repaired a fence on his property using standard tools and methods. A sudden gust of wind caused a board to fall and strike a passing cyclist, resulting in death. Because the repair was a lawful act done without criminal negligence, the killing qualified as accidental.
Aaron Adams drove within the speed limit on a clear day when a child darted from behind a parked car. The impact proved fatal. Adams had maintained a reasonable belief that no harm would occur under ordinary driving conditions, establishing the killing as accidental rather than criminally negligent.
Select any source to read its text and confirm it supports the definition.
Anthony Arnold committed a minor traffic violation by rolling through a stop sign. An unrelated medical emergency in another vehicle caused a fatal crash blocks away. The absence of a direct causal link from the unlawful act meant the death remained an accidental killing.
Audrey Ashton lit a permitted campfire in a designated area following all safety rules. An unexpected wind shift carried a spark to dry brush, causing a fatal burn injury to a nearby camper. The conduct stayed within lawful bounds and a reasonable belief of safety, rendering the killing accidental.
Aisha Ahmed administered prescribed medication exactly as directed by a physician. An undiagnosed allergy produced a fatal reaction. Because the act was lawful and performed without any deviation from reasonable care, the outcome constituted an accidental killing.
Accidental killing arises from a lawful act done lawfully with a reasonable belief that no harm would result. Involuntary manslaughter instead requires either criminal negligence creating a high risk of death or an unintentional killing during a non-felony unlawful act.
Supporting sources
No. The misdemeanor-manslaughter rule applies only when the death is proximately caused by the unlawful act. If the death results from an independent cause or the act creates no foreseeable risk, the killing remains accidental.
Criminal negligence requires a gross deviation from the reasonable-person standard that creates a high risk of death or serious bodily harm. Ordinary mistakes or unforeseeable outcomes under lawful conduct do not meet this threshold and leave the killing accidental.
Supporting sources
…originated hundreds of years ago,[^maj-52] and was a fixture of English common law until 1957 when Parliament declared that an unintentional killing during a felony would be classified as manslaughter.[^maj-53] The common-law rule was transplanted to the American Colonies, and its use continued largely unabated into the 20th century,…