73 . contributes to the protection of certain rights affected by those situations, such as personal freedom, the right to humane treatment, and life.296 It is considered that in those cases impunity will not be eradicated without the determination of the general responsibilities –of the State- and individuals –criminal and of any other nature of its agents or individuals-, which complement each other.297 Due to the nature and gravity of the facts, even more so if there is a context of systematic violation to human rights, the States are compelled to carry out an investigation with the mentioned characteristics, pursuant with the requirements of the due process. Non-compliance generates, in those assumptions, the State’s international responsibility.298 284. The obligation to investigate “not only results from the conventional rules of International Law obligatory for the States Parties, but it also derives from the domestic legislation that refers to the duty to investigate ex officio certain illegal behaviors.” 299 Thus, it corresponds to the States Parties to establish, pursuant with the procedures and through the bodies established in its Constitution and its laws, 300 which illegal behaviors will be investigated ex officio and regulate the regimen of criminal actions within the domestic procedure, as well as the rules that allow the victims or affected parties to file a complaint or exercise a criminal action and, if this is the case, participate in the investigation and the process. In order to prove that a specific resources, such as a criminal investigation, is adequate it will be necessary to verify that it is suitable to protect the juridical situation that has been allegedly violated.301 285. With regard to the freedom of expression, the appropriateness of criminal proceedings as the adequate and effective resource to guarantee it will depend on the act of omission that violated said right.302 If the freedom of expression of a person has been affected by an act that has also violated other rights, such as personal freedom, personal integrity, or life, the criminal investigation may be an adequate resource to protect that situation. Under other circumstances, it is possible that criminal proceedings are not the necessary means to guarantee the due protection of the freedom of expression. The use of criminal proceedings “shall correspond to the need to protect fundamental juridical rights from situations that imply grave damages to those rights, and it must be proportional to the magnitude of the damage caused.”303 296 Cf. case of the Pueblo Bello massacre v. Colombia, supra note 80, para. 145; Case of Heliodoro Portugal v. Panama, supra note 27, para. 115; and Case of La Cantuta v. Peru, supra note 84, para. 110.. 297 Cf. Case of Goiburú et al. v. Paraguay, supra note 53, para. 88. 298 Cf. Case of Velásquez Rodríguez, supra note 38, paras. 166 and 176; Case of Godínez Cruz, supra note 107, para. 175; Case of Cantoral Huamaní and García Santa Cruz v. Peru, supra note 87, para. 102; Case of the Miguel Castro Castro Prison v. Peru, supra note 44, para. 119; Case of Ximenes Lopez v. Brazil. Merits, Reparations, and Costs. Judgment of July 4, 2006. Series C No. 149, para. 147; Case of the Ituango Massacres, supra note 31, para. 297. 299 Case of García Prieto et al. v. El Salvador, supra note 53, para. 104. 300 Cf. The Word “Laws” in Article 30 of the American Convention on Human Rights. Advisory Opinion OC6/86, supra note 37, para. 32. 301 Cf. Case of Velázquez Rodríguez v. Honduras. Merits, supra note 38, 64. The Court has considered that the violations to Article 13 of the Convention could occur under different hypothesis, depending on if they lead to the suppression of the freedom of expression or they only imply a restriction beyond what is legally allowed. Cf. Compulsory Membership in an Association Prescribed by Law for the Practice of Journalism (Arts. 13 and 29 of the American Convention on Human Rights). Advisory Opinion OC-5/85, supra note 71, paras. 53 and 54; and Case of Ricardo Canese v. Paraguay, supra note 71, para. 77. 302 303 Case of Kimel v. Argentina, supra note 71, para. 77.