39 172. As pointed out in the section on international standards for criminal justice in the case of children and adolescents and the sentence of life imprisonment, the need for a periodic review is a function of the fact that juveniles under the age of 18 are deemed to have diminished culpability vis-à-vis adults who commit the same offenses. It is also a function of the fundamental objectives that sentences of imprisonment are to serve when the person convicted is a minor. As noted earlier, States undertake the obligation of providing education, treatment and care aimed at the child’s release, reintegration into society and ability to play a constructive role therein. In the Commission’s view, these obligations emanate from the fact that at the time the State assumes custody of a youth who committed crimes as a child, that child is at a critical stage in his/her personal and social development, deciding what he/she will do with his/her life and acquiring knowledge and skills that will be essential for life in society. 173. Thus, a periodic review to check these factors makes it possible to gauge the person’s rehabilitation process and eventually order that person’s release based on the progress made; the absence of such a review system takes a particularly heavy toll on the possibility of reform and social reintegration in the case of persons sentenced for crimes committed while they were still children, which is incompatible with the provisions of articles 5(6) and 19 of the American Convention, in relation to the obligations undertaken in articles 1(1) and 2 thereof. 6. An analysis to determine whether the sentences imposed upon the alleged victims constituted arbitrary deprivation of liberty and cruel and inhumane treatment 174. The petitioners alleged that the sentence of life imprisonment violated not only articles 5 and 19 of the Convention, but also the right not to be deprived of liberty arbitrarily. On the matter of arbitrary arrest or imprisonment, the Inter-American Court has written that In the case of the arbitrary arrest or imprisonment to which Article 7(3) of the Convention refers, the Court has previously held that no one shall be arbitrarily arrested or imprisoned for reasons and by methods that – though qualified as legal- may be deemed to be incompatible with respect for fundamental rights of the 135 individual, due, among other things, to their unreasonable, unforeseeable, or disproportionate nature. 175. Under certain circumstances, violations of international human rights standards committed when adopting decisions where a person’s liberty is at stake can make the arrest or imprisonment resulting from such decisions arbitrary. For example, one factor considered by the United Nations Working Group on Arbitrary Detentions to determine when an arrest or imprisonment can be classified as arbitrary is described as follows: When the total or partial non-observance of the international norms relating to the right to a fair trial, spelled out in the Universal Declaration of Human Rights and in the relevant international instruments accepted by the States concerned, is of such gravity as to give the deprivation of 136 liberty an arbitrary character. 176. Similarly, in its examination of violations of the right to a hearing by a competent and impartial judge, the Inter-American Court held that the effect of such violations could be a violation of the right to personal liberty recognized in Article 7(1) of the Convention. In the words of the Court: Brazil, 3 years; Chile, 5 years; Costa Rica, 15 years; Dominican Republic, 2 years; Ecuador, 4 years; El Salvador, 7 years; Guatemala, 5 years; Honduras, 8 years; Nicaragua, 6 years; Panama, 5 years; Peru, 3 years; Uruguay; 5 years; and Venezuela, 5 years. 135 I/A Court H.R., Case of García Asto and Ramírez Rojas. Judgment of November 25, 2005. Series C No. 137, para. 105; Case of Acosta Calderón. Judgment of June 24, 2005. Series C No. 129, para. 57; Case of Tibi. Judgment of September 7, 2004. Series C No. 114, para. 98; and Case of the Gómez Paquiyauri Brothers. Judgment of July 8, 2004. Series C No. 110, para. 83; I/A Court H.R., Case of Usón Ramírez v. Venezuela. Preliminary Objections, Merits, Reparations and Costs. Judgment of November 20, 2009. Series C No. 207, para. 146. 136 See. Fact Sheet No. 26. Working Group on Arbitrary Detention. Publication of the Office of the United Nations High Commissioner for Human Rights.