the events and to rebut allegations over its liability, through appropriate evidentiary elements.92 77. Similarly, the UN Human Rights Committee has held that in cases where further clarification depends on information exclusively in the hands of the State, allegations may be considered substantiated in the absence of satisfactory evidence or explanation to refute the claims of the petitioners.93 This is very much in line with the holding of the European Court to the effect that in cases of death as a consequence of the use of deadly force, the strictest test must be used on the compelling nature of said use of force.94 78. As such, in order for an explanation of the use of deadly force to be deemed satisfactory, it must be the fruit of an investigation that is compatible with guarantees of independence, impartiality and due diligence and, additionally, must meet certain requirements under Inter-American legal precedent in order to justify the use of force, which are: i. Legitimate purpose: the use of force must be aimed at achieving a legitimate purpose. (…) ii. Absolute necessity: it is necessary to verify whether other less harmful means exist to safeguard the life and integrity of the person or situation that is sought to protect, according to the circumstances of the case. (…) iii. Proportionality: the level of force used must be in accordance with the level of resistance offered, which implies striking a balance between the situation that the agent is facing and his response, considering the potential harm that could be caused.95 79. It follows from the aforementioned criteria that legitimate purpose, absolute necessity and proportionality of the use of force must be substantiated by the State in light of the particular circumstances of the specific case involved. Additionally, as a consequence of these principles, the Commission recalls that state agents who intervene in such operations must apply the criteria of “differentiated and progressive use of force, determining the degree of cooperation, resistance or violence of the subject against whom the intervention is intended and, on this basis, employ negotiating tactics, control or use of force, as required.”96 80. The Commission also notes that the Principles on the Use of Force provide for the use of firearms in “order to arrest a person presenting such a danger and resisting their authority.”97 Notwithstanding, as part of the requirements to authorize the use of force in said hypothetical situation, the Principles establish that: i) it may only be used only when other less extreme means are insufficient to achieve this purpose; ii) it must be used “when strictly unavoidable in order to protect life;” iii) officers must give a clear warning of their intent to use firearms;” and iv) this warning must be given with sufficient time 92 IA Court of HR. Case of Zambrano Vélez et al v. Ecuador. Merits, Reparations and Costs. Judgment of July 4, 2007. Series C No. 166, par. 108; Case of Cruz Sánchez et al v. Peru. Preliminary Objections, Merits, Reparations and Costs. Judgment of April 17, 2015. Series C No. 292, par. 291; and Case of Landaeta Mejías Brothers et al v. Venezuela. Preliminary Objections, Merits, Reparations and Costs. Judgment of August 27, 2014. Series C No. 281, par. 132. 93 UN, Human Rights Committee. Case of Irene Bleier Lewenhoff and Rosa Valiño de Bleier v. Uruguay. Communication No. 30/1978, UN Doc. CCPR/C/OP/1, of March 29, 1982, par. 13.3; Case of Albert Womah Mukong v. Cameroon. Communication No. 458/1991, UN Doc. CCPR/C/51/D/458/1991, of July 21, 1994, par. 9.2, and Case of Turdukan Zhumbaeva v. Kyrgyzstan. Communication Nº 1756/2008, UN Doc. CCPR/C/102/D/1756/2008, of July 29, 2011, par. 8.7. 94 ECHR, Case McCann and others v. The United Kingdom. Application No. 27229/95, 27 September 1995, § 149. IA Court of HR. Case of the Landaeta Mejías Brothers et al v. Venezuela. Preliminary Objections, Merits, Reparations and Costs. Judgment of August 27, 2014. Series C No. 281, par. 134. 95 96 IA Court of HR. Case of Nadege Dorzema et al v. Dominican Republic. Merits, Reparations and Costs. Judgment of October 24, 2012 Series C No. 251, par. 85. 97 Principles 9 and 10 of the UN Basic Principles on the Use of Force and Firearms adopted by the Eighth United Nations Congress on the Prevention of Crime and the Treatment of Offenders, in Havana, Cuba, August 27 to September 7, 1990. 15