A/HRC/21/50 31. Moreover, a state-sponsored deprivation of life will be arbitrary in the legal sense unless it is both necessary and proportionate. Therefore, when a state actor employs lethal force it must be in order to protect life (i.e., it must be proportionate) and there must also be no other means available, such as capture or incapacitation, to curtail that threat to life (i.e., it must be necessary). Only under these limited circumstances is the resort to lethal force by the State legal. 32. The noted IHRL standards differ to a degree from those applicable to fighters/combatants during an armed conflict under IHL. For example, one would not expect soldiers to warn their enemies before an attack. So long as all applicable IHL, CIL and IHRL requirements are met, killing an enemy fighter during an armed conflict is not illegal. The converse is also true: fighters/combatants causing another person‘s death, even that of the enemy, during armed conflict can be unlawful when the applicable law is breached (see below). 2. Murder as a war crime 33. In specific circumstances, killing another person during an armed conflict is murder (also known as ―wilful killing‖ when committed in the course of an international armed conflict). The crime of murder is a recognized offense under customary law and has been codified in the Rome Statute. In non-international armed conflict, the elements comprising the war crime of murder are as follows: (i) The perpetrator killed one or more persons; (ii) Such person or persons were either hors de combat, or were civilians, medical personnel, or religious personnel taking no active part in the hostilities; (iii) The perpetrator was aware of the factual circumstances that established this status; (iv) The conduct took place in the context of and was associated with an armed conflict not of an international character; (v) The perpetrator was aware of factual circumstances that established the existence of an armed conflict. 34. Thus, murder is committed upon the intentional killing of a protected person in the context of an armed conflict when the perpetrator is aware of the circumstances of the victim and the conflict itself. Interpretations given by the international courts to the elements of murder largely mirror those of traditional criminal law. For example, even where the perpetrator does not directly kill the victim at his own hand, the act(s) of the perpetrator must at least be a ―substantial cause of the death‖ of the victim. Premeditation does not appear as a required element. 35. Murder can also be prosecuted as a crime against humanity when it is perpetrated in the context of a widespread or systematic attack against any civilian population - whether conducted in a time of war or peace. The mental element of murder as a crime against humanity not only includes the intent to cause someone‘s death but also the knowledge of the act being part of a widespread or systematic attack against any civilian population. 3. Attacks on protected persons and objects; Indiscriminate attacks 36. IHL prohibits the intentional targeting of civilians in both international and noninternational armed conflicts. Violations of this provision are prosecutable in ICL, 53