70. Regarding the specific functions of prosecutors, on different occasions the Court has stressed the need for States to ensure an independent and objective investigation 45 into human rights violations and into crimes in general, and has emphasized that the authorities responsible for the investigation must enjoy de jure and de facto independence which requires “not only hierarchical or institutional independence, but also real independence.”46 71. The Court has also indicated that the requirements of due process established in Article 8(1) of the Convention, as well as the criteria of independence and objectivity also extend to the bodies responsible for the investigation conducted prior to the judicial proceedings in order to determine the existence of sufficient evidence for prosecuting a case; thus, if these requirements are not met, the State will be unable to exercise its prosecutorial powers effectively and efficiently and the courts will be unable to conduct the corresponding judicial proceedings.47 72. Based on the foregoing, the Court considers that the guarantees of an appropriate appointment, of tenure in office and of protection against external pressures also safeguard the work of prosecutors. Otherwise, the independence and objectivity required of their function would be jeopardized; principles aimed at ensuring that the investigations conducted and the charges filed before the jurisdictional organs are addressed exclusively at achieving justice in each case, consistent with the provisions of Article 8 of the Convention. In this regard, it should be added that the Court has stipulated that the absence of the guarantee of tenure for prosecutors, by rendering them vulnerable to reprisals for the decisions they take, results in a violation of the independence that Article 8(1) of the Convention ensures.48 73. This opinion is also supported by various international instruments and declarations. Indeed, the United Nations Guidelines on the Role of Prosecutors establishes the obligation of States to “ensure that prosecutors are able to perform their professional functions without intimidation, hindrance, harassment, improper interference or unjustified exposure to civil, penal or other liability.”49 Cf. inter alia, Case of Bueno Alves v. Argentina. Merits, reparations and costs. Judgment of May 11, 2007. Series C No. 164, para. 108; Case of Isaza Uribe et al. v. Colombia. Merits, reparations and costs. Judgment of November 20, 2018. Series C No. 363, para. 150, and Case of Martínez Esquivia v. Colombia, supra, para. 86. The following instruments also refer to these requirements among others: Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, 1984, Article 12; Inter-American Convention to Prevent and Punish Torture, 1985, Article 8; United Nations Convention against Corruption, 2003, Article 11(2), and International Convention for the Protection of All Persons from Enforced Disappearances, 2006, Article 12. See also: Principles on the Effective Prevention and Investigation of Extra-legal, Arbitrary and Summary Executions, recommended by the United Nations Economic and Social Council in its Resolution 1989/65, of May 24, 1989, Principle 9; Principles on the Effective Investigation and Documentation of Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, adopted by the General Assembly in the annex to Resolution 55/89 of December 4, 2000, Principle 2, and Committee against Torture, General Comment No. 2, Implementation of article 2 by States Parties, CAT/C/GC/2, January 24, 2008, para. 26. 45 Cf. Case of Baldeón García v. Peru. Merits, reparations and costs. Judgment of April 6, 2006. Series C No. 147, para. 95; Case of Montero Aranguren et al. (Retén de Catia) v. Venezuela. Preliminary objection, merits, reparations and costs. Judgment of July 5, 2006. Series C No. 150, para. 81, and Case of Martínez Esquivia v. Colombia, supra, para. 86. 46 Cf. Case of Cantoral Huamaní and García Santa Cruz v. Peru. Preliminary objection, merits, reparations and costs. Judgment of July 10, 2007. Series C No. 167, para. 133; Case of J. v. Peru. Preliminary objection, merits, reparations and costs. Judgment of November 27, 2013. Series C No. 275, para. 182, and Case of Martínez Esquivia v. Colombia, supra, para. 87. 47 Cf. Case of Valencia Hinojosa et al. v. Ecuador. Preliminary objections, merits, reparations and costs. Judgment of November 29, 2016. Series C No. 327, paras. 110 and 119, and Case of Martínez Esquivia v. Colombia, supra, para. 88. 48 Cf. Guidelines on the Role of Prosecutors, adopted at the Eighth United Nations Congress on the Prevention of Crime and the Treatment of Offenders, held in Havana, Cuba, from August 27 to September 7, 1990, UN Doc. 49 20