State agents and to identify and hold accountable individuals or groups responsible for violations of the right to life constitutes in itself a violation by the State of that right. This is even more the case where there is tolerance of a culture of impunity. All investigations must be prompt, impartial, thorough and transparent. (16) Effective systems and legal processes of police investigation (including capacity to collect and analyse forensic evidence) and accountability (including independent oversight mechanisms) should be established where they are not in place. (17) Accountability, in this sense, requires investigation and, where appropriate criminal prosecution. In certain circumstances, independent, impartial and properly constituted commissions of inquiry or truth commissions can play a role, as long as they do not grant or result in impunity for international crimes. Accountability also encompasses measures such as reparation, ensuring non-repetition, disciplinary action, making the truth known, institutional review and, where applicable, reform. States must ensure that victims have access to effective remedies for such violations. States should cooperate with international mechanisms so as to ensure accountability. (18) States must hold to account private individuals and corporations, including private military and security companies, that are responsible for causing or contributing to arbitrary deprivations of life in the State’s territory or jurisdiction. Home States also should ensure accountability for any extraterritorial violations of the right to life, including those committed or contributed to by their nationals or by businesses domiciled in their territory or jurisdiction. (19) Reparation should be proportional to the gravity of the violations and the harm suffered. Victims should be treated with respect and appropriate measures should be taken to ensure their safety. Those who have suffered violence or trauma should benefit from consideration to avoid re-traumatisation. Full and effective reparation to address the harm suffered by victims, including by their family and dependents, should include the implementation of guarantees of non-repetition. 11