Murder is the unlawful killing, with malice aforethought, of another human. Generally this premeditated state of mind distinguishes murder from other forms of unlawful homicide (such as manslaughter).Most societies both present and in antiquity have considered murder a most serious crime worthy of the harshest of punishment, under the justification that commission of murder is highly detrimental to good order within society. In most countries, a person convicted of murder is typically given a long prison sentence, possibly a life sentence where permitted, and in some countries, the death penalty may be imposed for such an act – though this practice is becoming less common.