investigations and 6 years after they were implicated in the case. In the opinion of this Commission, this has functioned as a mechanism for these acts to go unpunished, in light of the criminal statutes of limitation applicable in this case. 170. According to the information available, the Commission observes that line of investigation does not appear to be corroborated by any evidence, and is clearly contradicted by the conclusions drawn from the threats and the majority of the witness accounts. What’s more, there are no indications in the case file of a serious investigation into whether, as alleged, some of the defense witnesses gave false testimony at trial in this case to divert the investigation, clear the defendants of criminal wrongdoing, and enable their acquittal. It is an extremely serious accusation, which warrants a serious and timely investigation. 171. Accordingly, the IACHR considers that the measures taken to further the investigation have not been adequate and sufficient to satisfy the obligation of the State to conduct an exhaustive and diligent investigation, given the seriousness of the crime and the perverse effects that impunity has on society in these types of cases. d. Undue delay and the lack of substantial progress in the investigations 172. In compliance with its duty to pursue justice for acts of violence against journalists, States have the obligation to ensure that the investigations and criminal proceedings are conducted within a reasonable period of time. In this regard, the Inter-American Court has established that excessive delay in the investigation of acts of violence can per se be a violation of the right to a fair trial.157 The authorities responsible for the investigation must conduct the proceedings expeditiously, preventing improper delays or obstacles that lead to impunity and violate the proper judicial protection of the right.158 173. According to the inter-American case law, the reasonable time period established in Article 8(1) of the American Convention “This is not an easy concept to define”; rather, it must be interpreted in light of the complexity of the case, the judicial activity of the interested party, and the conduct of the judicial authorities,159 and the impairment to the legal situation of the person involved in the proceedings.160 174. In this regard, the Inter-American Court has established that the authorities responsible for an investigation must conduct the proceedings expeditiously, preventing improper delays or obstacles that lead to impunity and violate the proper judicial protection of the right.161 Accordingly, the IACHR has held that “as a general rule, a criminal investigation must be carried out promptly to protect the interest of the victims, preserve evidence and even to safeguard the rights of any person that is considered a suspect in the investigation.”162 157 I/A Court H.R., Case of Gómez Palomino v. Peru. Merits, Reparations and Costs. Judgment of November 22, 2005. Series C No. 136. Para. 85; I/A Court H.R., Case of the Moiwana Community v. Suriname. Preliminary Objections, Merits, Reparations and Costs. Judgment of June 15, 2005. Series C No. 124. Para. 160. 158 I/A Court H.R., Case of Gómez Palomino v. Peru. Merits, Reparations and Costs. Judgment of November 22, 2005. Series C No. 136. Para. 85. 159 I/A Court H.R., Case of Genie Lacayo v. Nicaragua. Merits, Reparations and Costs. Judgment of January 29, 1997. Series C No. 30. Para. 77; IACHR. Report No. 50/99. Case 11.739. Héctor Félix Miranda (Mexico). April 13, 1999. Para. 52; IACHR. Report No. 130/99. Case No. 11.740. Víctor Manuel Oropeza (Mexico). November 19, 1999. Para. 30. 160 Cfr. I/A Court H.R., Case of Kawas Fernández v. Honduras. Merits, Reparations and Costs. Judgment of April 3, 2009. Series C No. 196. Para. 112; Case of Valle Jaramillo et al. v. Colombia. Merits, Reparations and Costs. Judgment of November 27, 2008. Series C No. 192. Para. 155. 161 I/A Court H.R., Case of Gómez Palomino v. Peru. Merits, Reparations and Costs. Judgment of November 22, 2005. Series C No. 136. Para. 85. 162 IACHR. Office of the Special Rapporteur for Freedom of Expression. Special Study on the Status of Investigations into the Murder of Journalists during the 1995-2005 Period for Reasons That May Be Related to Their Work in Journalism. OEA/Ser.L/V/II.131. Doc. 35. March 8, 2008, para. 60.