II. The Broad Scope of Due Process of Law. 12. One of the central issues in the Case of the “Juvenile Reeducation Institute” that the Court examined in the Judgment it just delivered, is that of preventive imprisonment [or preventive detention or preventive custody]. In practice, preventive imprisonment has become a curse now afflicting thousands and thousands of forgotten souls in detention centers around the world. In its Judgment in this case, the Court warns against the excesses and abuses of this practice, pointing out that preventive detention must be for the shortest time possible. The Court also reminds us of the special precautions that must be taken when children are deprived of their liberty. And, as the Court also points out, preventive imprisonment is limited by universally recognized general principles of law (such as the presumption of innocence and the principles of necessity and proportionality). If those principles are not being observed, then preventive detention becomes an unlawful form of advance punishment without conviction (paragraphs 229-231). At the substantive level and in keeping with the case law that the Court established in the Case of the “Street Children” (Merits, 1999), the Court uses the concept of the right to life latu sensu, so that it also encompasses the right to live in dignity (paragraphs 151-152, 156, 160-161, 164, 167-168 and 170).
13. Here, once again, the role and importance of the general principles of law that, on a broader plane, permeate and steer due process of law as a whole, become more self-evident. In Advisory Opinion OC-9/87, on Judicial Guarantees in States of Emergency, the Inter-American Court had occasion to clarify the broad scope of due process of law under Article 8 of the American Convention on Human Rights. The Court wrote that Article 8 includes the procedural requirements and prerequisites that courts must observe in order to ensure adequate protection of those persons whose rights or obligations are pending judicial determination; in other words, in order for those requirements and prerequisites to function as real judicial guarantees in the sense of the American Convention.11 The concept of due process of law expressed in Article 8 of the Convention should be understood to apply to all judicial guarantees referred to in the American Convention (reading Article 8 in combination with Articles 7(6), 25 and 27(2) of the Convention).12 14. That being the case, judicial guarantees such as those protected under American Convention articles 7(6) -habeas corpus– and 25(1) –the petition for a writ of amparo or the petition for a writ of mandamus or any other effective remedy before the competent domestic judges or courts- are essentials that must be taken within the framework of the principles of Article 8 of the Convention.13 The Court concludes Advisory Opinion OC-9 in very unambiguous terms:
"the above judicial guarantees should be exercised within the framework and the principles of due process of law, expressed in Article 8 of the Convention. "14