16 particular pretrial detention, as a measure of last resort.” Every child or adolescent who is criminally prosecuted must be treated justly and have an impartial trial, which fully adheres to the due process guarantees set forth in Article 40.2 of the Convention on the Rights of the Child, Article 14 of the International Covenant on Civil and Political Rights, Article 8 and Article 25 of the American Convention on Human Rights. These guarantees include the prohibition of ex post facto application of criminal laws, the presumption of innocence, the right to be heard, the right to effective participation in the proceedings, the right to receive direct and speedy information on the charges, the right to legal or any other appropriate assistance, the right to speedy decision with the participation of the parents, the right to the presence and examination of witnesses, the right to 17 appeal, the right to the free assistance of an interpreter and full respect for his or her private life. In this regard, the Committee on the Rights of the Child has emphasized that “a key condition for a proper and effective implementation of these rights or guarantees is the quality of the persons involved in the administration of juvenile justice. The training of professionals, such as police officers, prosecutors, legal and other representatives of the child, judges, probation officers, social workers and others is crucial and should take place in a systematic and ongoing manner. These professionals should be well informed about the child’s, and particularly about the adolescent’s physical, psychological, mental and social development, as well as about the special needs of the most vulnerable children, such as, (…) children belonging to racial, ethnic, religious, linguistic or 18 other minorities (…).” Respect for the right of indigenous children to be heard and for their opinions to be taken into account, in accordance with Article 12 of the Convention on the Rights of the Child, is equally as important. The Committee on the Rights of the Child has explicitly stated on this topic that “with regards to the individual indigenous child, the State party has the obligation to respect the child’s right to express his or her view in all matters affecting him or her, directly or through a representative, and give due weight to this opinion in accordance with the age and maturity of the child. The obligation is to be respected in any judicial or administrative proceeding. Taking into account the obstacles, which prevent indigenous children from exercising this right, the State party should provide an environment that encourages the free opinion of the child. The right to be heard includes the right to representation, culturally appropriate interpretation and also the right not to 19 express one’s opinion.” The Committee has also reminded States parties that pursuant to Article 12 of the Convention on the Rights of the Child, “all children should have an opportunity to be heard in any judicial or criminal proceedings affecting them, either directly or through a representative. In the case of indigenous children, States parties should adopt measures to ensure that an interpreter is provided free of charge, if required, and that the child is guaranteed legal assistance, in a 20 culturally sensitive manner.” It is noted that some of the Mapuche juveniles being prosecuted under the anti-terrorist law are currently being held in preventive detention, which goes against the grain of the international standards that are binding on the Chilean State. The rule of deprivation of liberty as a last resort stems from the need to protect the right to development of children and adolescents in conflict with the law. In the view of the Committee on the Rights of the Child, “the use of deprivation of liberty has very negative consequences for the child’s harmonious development and seriously hampers his/her reintegration in society. In this regard, article 37 (b) explicitly provides that deprivation of 16 UN Committee on the Rights of the Child: General Comment No. 10 (2007)- Children’s Rights in Juvenile Justice. UN Document CRC/C/GC/10, April 25, 2007, par. 28. 17 UN Committee on the Rights of the Child: General Comment No. 10 (2007)- Children’s Rights in Juvenile Justice. UN Document CRC/C/GC/10, April 25, 2007, pars. 40-67. 18 UN Committee on the Rights of the Child: General Comment No. 10 (2007)- Children’s Rights in Juvenile Justice. UN Document CRC/C/GC/10, April 25, 2007, par. 40. 19 UN Committee on the Rights of the Child: General Comment No. 11 (2009)- Indigenous Children and their Rights under the Convention. UN Document CRC/C/GC/11, February 12, 2009, par. 38. 20 UN Committee on the Rights of the Child: General Comment No. 11 (2009)- Indigenous Children and their Rights under the Convention. UN Document CRC/C/GC/11, February 12, 2009, par. 76.