2 the measure; at times they are administrative (an increasingly frequent situation), in order to combat criminal acts, based on arguments of urgency and public safety, but certainly disquieting and dangerous. 5. The fact that restrictions to the exercise of the rights of the individual – entailing, if we examine this realistically, a real temporary deprivation of those rights (for example, preventive detention) – occur before a judgment has been delivered (and, often, even before the trial commences), evidently creates tension between such measures, extensively embodied in law and applied in the practice, on the one hand, and the principle or presumption of innocence, on the other hand. The latter is a prized general guarantee for the individual, prior to the time when he faces criminal proceedings or while such proceedings are underway, and the Inter-American Court’s case law recognizes this to be the foundation or basis for the rights embodied in the notion of due process. It is difficult to conciliate the presumption that someone is innocent of the unlawful conduct attributed to him or that is being investigated in order to attribute it to him, with the infringement of his rights as a means or instrument – paradoxically – to define whether the alleged conduct exists and to prove hypothetical responsibility. 6. In these circumstances, there is an evident element of injustice in punitive preventive measures that limit rights, invade privacy and restrict liberty. However, there appear to be no doubts about the need or inevitability of adopting measures of this nature in the interest of criminal justice as a whole, the probable rights of victims, public peace, etcetera, factors that help alleviate the tensions to which I referred and “pacify the conscience of justice” with persuasive arguments based, above all, on reasons of security. We have been unable to eradicate – and will be unable to do so for a long time, or perhaps ever – the need for preventive measures that are more or less rigorous. The most we can and, obviously, should do is to reduce them to their most essential form and substitute them, whenever possible, by instruments that have a less harmful effect on rights and that are sufficiently effective for the satisfactory administration of criminal justice. 7. In brief, therefore, as in the case of any other restriction of fundamental rights, punitive preventive measures must be: (a) exceptional, rather than regular, routine and systematic; (b) justified within a precise framework of reasons and conditions that provide them with legitimacy and rationale; (c) agreed on by an independent, impartial and competent jurisdictional authority, that decides on them formally and states the reasons and grounds on which they are based; (d) essential to achieve their legitimate purpose; (e) proportionate to this purpose and to the circumstances in which they are issued; (f) limited, to the extent possible, in intensity and duration; (g) periodically reviewable, by law and at the request of the parties; a review that include the guarantees inherent in a real impugning system (independence, effectiveness and promptness); and (h) able to be revoked or substituted when their reasonable duration has been exceeded, taking into account their characteristics. All of this, which is applicable to the general system of punitive preventive measures, has a special importance if we consider the most severe of such measures: the preventive deprivation of liberty. C) Preventive deprivation of liberty a) Conditions 8. It is frequently and rightly said that the criminal justice system – particularly the one used in the countries encompassed by the Inter-American system – makes excessive use of preventive detention and remand in custody. Abundant information exists to illustrate this affirmation. There are many supposed offenses for which the alleged authors