Homicide is the act of one human killing another. A homicide requires only a volitional act by another person that results in death, and thus a homicide may result from accidental, reckless, or negligent acts even if there is no intent to cause harm. Homicides can be divided into many overlapping legal categories, including murder, manslaughter, justifiable homicide, killing in war (either following the laws of war or as a war crime), euthanasia, and capital punishment, depending on the circumstances of the death.