Manslaughter is a homicide that is a serious felony, but is considered less serious than murder. While punishable by many years in prison, the punishment is therefore typically less than that for murder.
There are two basic types of manslaughter: voluntary (which is sometimes called first-degree) manslaughter and involuntary (or second-degree) manslaughter.
Voluntary manslaughter applies to intent-to-kill homicide, but where the crime was committed in the “heat of passion” after provocation, making it a less serious crime than intentional murder. Some states also apply voluntary manslaughter where the defendant intended to cause serious bodily harm and the victim died.
Involuntary manslaughter typically applies where the defendant’s reckless or criminally negligent actions caused the death of another person. The classic example here is where drunk driver gets into a car accident that kills another person.