A/HRC/14/40 52. Experts recalled that the principle of proportionality plays a very important role in the European Court’s case-law. In several cases the Court examined whether the use of force was proportionate to the legitimate aims pursued, whether a fair equilibrium was reached between the aim expected and the means employed, and whether this use was absolutely necessary. 53. It was also pointed out that the European Court’s case-law insists on procedural aspects of the rights to life, one of them being the right of the family to a thorough, prompt and effective investigation into the killing of a person. The procedural aspect comprises a State’s obligation to investigate, prosecute and punish violations of the right to life. In the Court’s case-law all serious human rights violations must be subject to a prompt, impartial, thorough and independent official investigation. The Court has not hesitated to apply the requirement to investigations in situations of armed conflicts. Indeed, the fact that a killing might be justified under international humanitarian law does not preclude the right to an investigation. This was indicated in particular in the case of Kaya v. Turkey, in which the Court stated that neither the prevalence of violent armed clashes nor the high incidence of fatalities can displace the obligation to ensure that an effective, independent investigation is conducted into death arising out of clashes involving the security forces. V. Session 4: Other actors that contribute to the implementation of human rights in armed conflicts 54. Concerning the contribution of other mechanisms to the implementation of international human rights in armed conflict situations, experts pointed out to the important work done by international commissions of inquiry. Mention was made to the Commission of Inquiry on Darfur established pursuant to Security Council resolution 1564 (2004), as well as to commissions of inquiry established under the Human Rights Council mandate, including the United Nations Fact Finding Mission on the Gaza Conflict. 55. It was pointed out that commissions of inquiry do not operate as a court of law, but instead use different methods and investigating procedures, including in relation to gathering, analysis and evaluation of information. The Darfur and the Gaza commissions of inquiry, for example, based their conclusions on credible information that showed that violations had occurred. Commissions of inquiry use standards for evaluating prima facie evidence that are less strict than those used by courts. The information they gather provide sufficient factual grounds to support findings related to allegations of human rights and humanitarian law violations. Moreover, evidence produced in the context of investigations of commissions of inquiry may further serve as a starting point for criminal investigations at the domestic and international levels. 56. Experts further indicated that investigations and conclusions of commissions of inquiry often lead to an in-depth analysis of domestic justice mechanisms in order to assess whether accountability for gross human rights violations and serious violations of international humanitarian law can be guaranteed, in line with States’ international law obligations to investigate, prosecute and punish alleged perpetrators of such violations. For instance, both the Darfur factfinding mission and the Gaza commission of inquiry assessed whether the relevant parties had established mechanisms to ensure accountability for violations, taking into account fairness and due process obligations. 57. Experts also highlighted that civil society organizations have been actively involved in the application of international human rights and international humanitarian law in their evaluation of the effects and consequences of armed conflict situations. Some international non-governmental organizations, for example, have undertaken field missions and have submitted analytical reports in relation to a number of conflicts. Their analyses take into 13