Involuntary manslaughter is a criminal offense defined as the unintentional killing (homicide) of another person as a result of criminal negligence, recklessness, or during the commission of a misdemeanor (driving while intoxicated), infraction (speeding), or a felony crime that was not inherently dangerous. Involuntary manslaughter is usually a felony offense and often includes significant jail or prison time as potential punishment.

Involuntary manslaughter laws vary from state to state and are generally located in a state’s statutes—often in the penal or criminal code.

In Massachusetts, involuntary manslaughter is defined as an unlawful killing that was unintentionally caused as the result of wanton or reckless conduct, or during the commission of a dangerous battery. It differs from murder in that there is no malice aforethought. Wanton or reckless conduct means the defendant created a high degree of likelihood that substantial harm would result to another. Involuntary manslaughter is considered a felony in Massachusetts. The punishment for involuntary manslaughter under Massachusetts law can be severe, with potential sentences including imprisonment in the state prison for up to 20 years. These laws are codified in the Massachusetts General Laws, specifically under Chapter 265, which covers crimes against the person, including homicide. It is important for individuals facing such charges to seek the counsel of an experienced attorney who can provide legal representation and navigate the complexities of the state's criminal justice system.