Homicide is the intentional killing of one person by another. Many societies consider homicide to be a serious crime and may punish offenders with imprisonment, death penalty or other severe penalties. Criminal homicide is divided into the categories of murder and manslaughter, depending on the extent to which a person intended to kill and how they killed that person.
The legal classification of homicides is important to understand because different categories carry distinct consequences and charges. For example, first-degree murder involves premeditation and deliberation and requires a specific intent to kill; second-degree murder is an intentional killing without such prior planning and is considered less serious.
In addition, there are other categories of homicide that are not crimes such as self-defense, justifiable homicide or killing in the course of a war (see below). Similarly, some types of homicide are considered medical acts such as euthanasia and infanticide, while others are considered ethically and morally acceptable such as a physician’s decision to help a terminally ill patient die.
Statistically, the incidence of homicide varies between countries and within countries depending on sociocultural factors. For example, a country with strict laws regarding weapon ownership has a lower incidence of homicide than one where the availability of firearms is high. Other variables that affect homicide rates include urbanization, population density and the degree to which a society is controlled by law and order. In general, cities have higher homicide rates than rural areas with a low level of social control.