What is the term used when a person intends to cause serious bodily injury but causes death instead?

The term that accurately describes a situation where a person intends to cause serious bodily injury but ultimately causes death is murder. This is because, in the context of legal terminology, murder typically involves the act of causing the death of another individual with malice aforethought, which includes intention to inflict serious harm that results in death. The key element here is the perpetrator's intention; while they may not have intended to kill, their intent to inflict serious bodily harm establishes the necessary mental state for murder.

In broader legal contexts, murder encompasses various degrees, often influenced by the specific intentions and circumstances surrounding the act. Thus, the critical distinction lies in the intent to cause serious harm, which can lead to a fatal outcome, classifying the act under murder in many jurisdictions.

This understanding differentiates it from other terms, such as involuntary manslaughter, which involves unintentional killing resulting from reckless behavior, or assault causing death, which is not commonly a recognized legal term. Intentional homicide would usually imply an explicit desire to kill, making murder the most fitting choice here.