5 witnesses and the delivery of the copies of some files belonging to officers of the armed forces, among other measures, “which were requested by the Asociación ProBúsqueda and not by the Prosecutor's Office”. In addition, on two occasions, the Attorney General’s Office requested the President of El Salvador, at the instance of the Chalatenango Trial Court, to provide a list of the officers that participated in the socalled “Operación Limpieza” (Operation Clean-Up), a military operation in which the Serrano-Cruz sisters were abducted. On July 17, 2009, the President of El Salvador instructed the Ministry of National Defense to provide that information, but so far there has been no response. 13. The representatives pointed out that the State “has taken no concrete steps to ascertain the whereabouts of the [victims], neither through the criminal proceedings pending before the Chalatenango Court nor through other measures.” They added that “no perpetrator has been identified, let alone punished […]. Since the Judgment was rendered in 2005, no investigation has been initiated by any judge or prosecutor. The only steps taken have been at the instance of the family’s legal representation.” Also, they expressed concern over the fact that the only measure taken by the court hearing the case, on its own motion, was to summon, a few days ago, Suyapa Serrano Cruz to appear in court at the same date and time as the private hearing regarding compliance with judgment before the Inter-American Court. Further, they stated that nothing has been done to remedy the numerous omissions and oversights by the judicial authorities which show that there is no clear line of investigation aimed at uncovering the truth about what happened to the girls. Once again, “the investigation into the facts of the case is currently inactive pending the answer from the President to the letter in which he [was] required to provide information […] and no other step has been taken by judicial authorities.” Finally, the representatives pointed out that the State “has not adopted any measures to punish the officials that obstructed justice in this case.” 14. The Commission pointed out that "the State has the general obligation to investigate” and, therefore, “the request that has not been fulfilled by the executive branch, namely by the Ministry of Defense, is not an isolated instance, [although it is] a step of paramount importance to the identification of those responsible […], which may represent a breakthrough in the investigation at the domestic level.” The Commission added that “the obligation to search for the victims is a very important obligation in this case, which is closely related to the investigation, but also to other forms” of reparation. 15. The Court reiterates what it has held in the Judgment and in its uniform case law since the first case brought before it, i.e. that the obligation to investigate must be taken “seriously, and not as a mere formality preordained to be ineffective.” [The investigation] must be conducted in a purposeful manner and undertaken by the State as its own legal duty and not as a mere pursuit of private interests, dependent on the initiative of the victim or their next of kin or upon evidence offered by them, without an effective search for the truth by public authorities.”7 7 Cf. Case of Velásquez-Rodríguez v. Honduras. Merits. Judgment of July 29, 1988. Series C No. 4, para. 177; Case of the “Five Pensioners”, supra note 2, Considering clause No. 15; and Case of ValleJaramillo et al. v. Colombia. Merits, Reparations, and Costs. Judgment of November 27, 2008. Series C No. 192, para. 100.