39 States to guarantee the free and full exercise of the rights recognized by the Convention to all persons subject to their jurisdiction (Article 1.1).192 202. The jurisprudence of the Inter-American system has established that even though the duty to investigate is an obligation of means not of results, it must be assumed by the State as its own legal duty, and not as a mere formality preordained to be ineffective,193 nor as a step taken by private interests depending on the initiative of the victims or their families or upon their offer of proof. 194 203. The Court has determined that the investigations undertaken by the State must be made with due diligence so that the enquiries are made utilizing all legal means available and are oriented toward the determination of the truth.195 In this sense, the Inter-American Commission has stated that the fact that no one has been convicted in the case or that, despite the efforts made, it was impossible to establish the facts does not constitute a failure to fulfill the obligation to investigate. However, in order to establish in a convincing and credible manner that this result was not the product of a mechanical implementation of certain procedural formalities with the State genuinely seeking the truth, the State must show that it carried out an immediate, exhaustive and impartial investigation. 196 204. The Inter-American Court has established that a long delay may per se constitute a violation of the principle of due process,197 and it is for the State to explain and prove why it has required more time than would be reasonable to deliver final judgment in a specific case. 198 The reasonability of the time period must be analyzed with regard to the total duration of the criminal process. In criminal matters this period of time starts when the first procedural act against a specific person as the probable responsible for a certain crime is presented and ends with the issuing of a definitive judgment.199 205. In its consistent jurisprudence, the organs of the Inter-American system have considered three elements that are relevant to an analysis of the present case, that is: a) the complexity of the case; b) the 192 I/A Court H.R., Cf. Case of Godínez Cruz v. Honduras. Preliminary Objections. Judgment of June 26, 1987. Series C No. 3, para. 93. See also the Case of the la Rochela Massacre v. Colombia, supra note 7, para. 145, and Case of the Miguel Castro Castro Penitentiary v. Peru, Judgment of November 25, 2006. Series C No. 160, paras. 183. 193 I/A Court H.R., Case of Velásquez Rodríguez v. Honduras. Judgment of July 29, 1988. Series C No. 4, para. 177; I/A Court H.R., Case of Cantoral Huamaní and García Santa Cruz v. Peru. Preliminary Objections, Merits, Reparations and Costs. Judgment of July 10, 2007. Series C No. 167, para. 131; and I/A Court H.R., Case of Zambrano Vélez et. al. v. Ecuador. Merits, Reparations and Costs. Judgment of July 4, 2007. Series C No. 166, para. 120. 194 I/A Court H.R., Case of Velásquez Rodríguez v. Honduras. Judgment of July 29, 1988. Series C No. 4, para. 177; I/A Court H.R., Case of Zambrano Vélez et. al. v. Ecuador. Merits, Reparations and Costs. Judgment of July 4, 2007. Series C No. 166, para. 120. 195 I/A Court H.R., Case of García Prieto et. al. v. El Salvador. Preliminary Objections, Merits, Reparations and Costs. Judgment of November 20, 2007. Series C No. 168, para. 101. 196 IACHR, Annual Report 1997, Report No. 55/97, Case 11.137 (Juan Carlos Abella et. al.), Argentina, para. 412. On the same point, see also: IACHR, Annual Report 1997, Report No. 52/97, Case of 11.218 (Arges Sequeira Mangas), Nicaragua, para. 96 and 97. [54] The Inter-American Court has stated, for example, that “the American Convention guarantees everyone access to justice to enforce their rights, and the States Parties have the obligation to prevent, investigate, identify and punish the masterminds and accessories of human rights violations.” I/A Court H.R, Case of the Constitutional Court, Judgment of January 31, 2001. Series C Nº 71, para. 123. See also I/A Court H.R, Case of Blake, Reparations, Judgment of January 22, 1999, Series C Nº 48, para. 65. 197 I/A Court H.R., Case of García Asto and Ramírez Rojas v. Peru. Judgment of November 25, 2005. Series C No. 137, para. 166; Case of Gómez Palomino v. Peru. Judgment of November 22, 2005. Series C No. 136, para. 85; Case of the Moiwana Community v. Surinam. Judgment of June 15, 2005. Series C No. 124, para. 160. 198 para. 142. I/A Court H.R., Case of Ricardo Canese v. Paraguay. Judgment of August 31, 2004. Series C No. 111, 199 I/A Court H.R., Case of López Álvarez v. Honduras. Judgment of February 1, 2006. Series C No. 141, para. 129; Case of Acosta Calderón v. Ecuador. Judgment of June 24, 2005. Series C No. 129, para. 104; and Case of Tibi v. Ecuador. Judgment of September 7, 2004. Series C No. 114, para. 168.