(2017) 1 African Human Rights Yearbook 5 the death penalty,10 and perpetration of killings by law enforcement officials. This last group embraces killings perpetrated by the police or by the military performing police function such as the killing of a suspect during an encounter with law enforcement officials; killing of a detainee by the police or prison guards (custodial death); and killing during law enforcement operations resulting from the disproportionate, unnecessary or excessive use of force and firearms in contravention of international standards set out particularly in the Basic Principles on the Use of Force and Firearms by Law Enforcement Officials (1990). In international human rights law, the protection of human rights is primarily the responsibility of the State as the main actor in the international and domestic planes. Any act, such as extrajudicial killing, which violates international human rights law, is in principle imputable to the State on the sufficient reasoning that the State failed in its due diligence obligation. It does not matter whether the act is done by a public official, or by persons who use their position of authority, or by individuals acting in the capacity of an agent of the State. In all cases of killing by State actors the State is held directly responsible for the extrajudicial killing because the protection of human rights, international and municipal, is primarily the responsibility of the State as the main actor internally and externally. Under human rights law the State is not only prohibited from directly violating the right to life. It is also required to ensure the right to life and must meet its due diligence obligations by taking appropriate measures to deter, prevent, investigate, prosecute and punish perpetrators. The State has positive obligations under international human rights law to ensure that rights of individuals are fully protected against violations by its agents. Failure to ensure the individual is not arbitrarily deprived of his life as required by article 4 of the African Charter will be tantamount to a violation of that right by the State. This is so because in such a case the State is deemed to have permitted the killing perpetrated by its agent or to have failed to take appropriate measures or exercise due diligence to prevent, punish, investigate or redress it. If any provision of a human rights treaty is broken, responsibility follows. The violation of the treaty by the State is a breach of the treaty and engages its responsibility. It is irrelevant whether the violation is by the State as national policy or by officials acting under cover of law or by persons for whose acts the State is responsible because such acts have been encouraged or condoned by it. 2.3 Killings by non-state actors The term ‘non-state actors’ includes corporations and nongovernmental organisations.11 In the context of perpetrators of 10 C Anyangwe ‘Emerging African jurisprudence suggesting the desirability of the abolition of capital punishment’ (2015) 23 African Journal of International and Comparative Law 1. 11 P Alston (ed) Non-state actors and human rights (2002).