an expression of the State’s punitive power and that, on occasions, the nature of the former is similar to that of the latter. They both entail impairment, deprivation or alteration of the rights of the individual, as a consequence of unlawful conduct. Therefore, in a democratic system it is necessary to take extreme care to ensure that the said measures are adopted with strict respect for the basic rights of the individual, and subject to a careful verification of the existence of the unlawful conduct. In addition, and to ensure legal certainty, it is essential that the punitive norm, whether criminal or administrative, exists and is known or can be known, before the act or omission occurs that violates it and for which punishment is intended. The definition of an act as being unlawful, and the determination of its legal effects must precede the conduct of the individual who is considered to be an offender. Otherwise, the individual would be unable to adjust his or her behavior in accordance with a valid and certain legal system that expresses the reproach of society and its consequences. These are the grounds for the principles of legality and the non-retroactivity of an unfavorable punitive norm.149 (Underlining added) 114. Furthermore, the ICourtHR has stated that the principle of legality constitutes one of the central elements of criminal prosecution in a democratic society by establishing that “no one may be sentenced for acts or omissions that, at the time they were committed, were not illegal under the applicable law.” This principle governs the actions of all the organs of the State, within their respective competences, particularly when the time comes to exercise punitive powers.150 The Inter-American Court has also indicated that the principle of non-retroactivity is also intended to prevent an individual from being punished for an act that, when committed, was not an offense or that was not punishable or could not be prosecuted.151 Additionally, the ICourtHR has established that the application of an administrative sanction or punishment that is substantially different to that established by law violates the principle of legality, because it is based on extensive interpretations of the criminal law.152 115. Consequently, there are two additional arguments that allow us to subsume what happened with regard to the impeachment proceedings into Article 9 of the American Convention. First, it should be considered that the “principle of legality” contains not only aspects relating to the existence of a prior law and sanction that explicitly mentions the literal meaning of the principle,153 but also the guarantee of the principle of criminalization. The principle of criminalization means that the punitive law must define with sufficient detail the elements that constitute the offense. 154 Thus, not only must the guarantees of due Cf., inter alia, Eur. Court H.R. Ezelin judgement of 26 April 1991, Series A no. 202, para. 45; and Eur. Court H.R. Müller and Others judgement of 24 May 1988, Series A no. 133, para. 29. 149 Cf. Case of Baena Ricardo et al. v. Panama. Merits, reparations and costs, para. 107, and Case of Fermín Ramírez v. Guatemala. Merits, reparations and costs, para. 90; Case of Mohamed v. Argentina, para. 130. 150 Cf. Case of Ricardo Canese v. Paraguay. Merits, reparations and costs. Judgment of August 31, 2004. Series C No. 111, para. 175, and Case of García Asto and Ramírez Rojas v. Peru. Preliminary objection, merits, reparations and costs. Judgment of November 25, 2005. Series C No. 137, para. 191, and Case of Mohamed v. Argentina, para. 131. 151 Cf. Case of Vélez Loor v. Panama. Preliminary objections, merits, reparations and costs. Judgment of November 23, 2010. Series C No. 218, para. 187. 152 Cf. Case of Vélez Loor v. Panama. Preliminary objections, merits, reparations and costs. Judgment of November 23, 2010. Series C No. 218, para. 183 (“in the interest of legal certainty, it is essential that the punitive norm, whether criminal or administrative, exists and is known or may be known, before the act or omission that violates it, and which it is intended to punish. The definition of an act as illegal, and the establishment of its legal effects must precede the conduct of the individual who is considered an offender. Otherwise, the individual would be unable to adapt his or her behavior in accordance with a valid and certain legal system that expresses the reproach of society and its consequences. These are the grounds for the principles of legality and of the nonretroactivity of an unfavorable punitive norm”). See also Case of Baena Ricardo et al. v. Panama. Merits, reparations and costs. Judgment of February 2, 2001. Series C No. 72, para. 106; Case of Yvon Neptune v. Haiti. Merits, reparations and costs. Judgment of May 6, 2008. Series C No. 180, para. 125, and Case of García Asto and Ramírez Rojas v. Peru. Judgment of November 25, 2005. Series C No. 137, para. 191. 153 Regarding criminal offenses, in the Case of García Asto and Ramírez Rojas v. Peru, the ICourtHR established that “definitions of crimes must clearly describe the criminalized conduct, establishing its elements, and 154 31