30 119. Thus, international human rights law establishes that no person may be convicted of a crime unless there is full proof of his or her criminal responsibility. As the Court has said, “if the evidence presented is incomplete or insufficient, he must be acquitted, not convicted.”172 Consequently, the Court has ruled that the absence of full evidence of criminal responsibility in a conviction constitutes a violation of the principle of presumption of innocence.173 120. The case under analysis raises two questions that are directly related to the principle of presumption of innocence. The first involves the claim of a lack of due diligence in the identification of Mr. José Agapito Ruano Torres as one of suspects in the crime for which he was convicted. The second involves the evidence on which that conviction was based. 1.1 The identification of Mr. Ruano Torres 121. The Commission believes that the principle of presumption of innocence, taken in conjunction with the principle of individual responsibility, imposes a minimum obligation on states as regards due diligence in the identification of persons who are to be subjected to investigations and criminal prosecutions. Only through their accurate identification can the competent authorities analyze and assess the evidence that exists regarding their possible involvement in an incident and their possible criminal responsibility. 122. According to the established facts, José Agapito Ruano Torres was first identified as one of the suspects in the kidnapping of Mr. Rodríguez Marroquín on October 12, 2000, during the police investigation carried out to locate “el Chopo,” the alias used by one of the suspected perpetrators of that abduction, as indicated by one of the participants in the crime, Francisco Amaya Villalta, in an extrajudicial statement given on October 9, 2000. 123. Thus, the police identification deed of October 12, 2000, indicates that “we sought to obtain information on the identity of the individual referred to only as Chopo, where we were told that he responded to the name of Agapito Ruano.” The Commission notes that neither this document nor any other part of the case file indicates the formalities pursued by the police officers on that date to identify José Agapito Ruano Torres as Chopo. During the pre-trial hearing held before the Second Trial Court, the police officer in charge of the case, who signed the police deed of October 12, 2000, stated that he did not recall the formalities carried out to identify the suspects in the kidnapping. 124. As for the judicial statement of Francisco Amaya Villalta given under the plea bargain admitted by the Justice of the Peace of Tonacatepeque on October 16, 2000, the Commission notes that it is a verbatim copy of the extrajudicial statement made on October 9, 2000. The sole difference is the inclusion of the name of José Agapito Ruano Torres whenever reference is made to the participation of Chopo in the kidnapping. Taking into account the full contents of the case file up to that date, the Commission understands that the inclusion of Mr. Ruano Torres’s name with the alias Chopo in the judicial statement of October 16, 2000, was made on the basis of the police operation of October 12, 2000. 172 I/A Court H. R., Case of Cantoral Benavides v. Peru, Judgment of August 18, 2000, Series C No. 69, para. 120; and I/A Court H. R., Case of Ricardo Canese v. Paraguay, Judgment of August 31, 2004, Series C No. 111, para. 153. 173 I/A Court H. R., Case of Cantoral Benavides v. Peru, Judgment of August 18, 2000, Series C No. 69, para. 121.