BOUYID v. BELGIUM JUDGMENT 15 Recommendation, § 52.1).The latter emphasises that “children’s fragility and vulnerability and their dependence on adults for the[ir] growth and development call for greater investment in the prevention of violence and protection of children on the part of families, society and the State”. Very recently the CPT highlighted the particular vulnerability of juveniles in the context of detention (24th General Report of the CPT, 2013-2014 (CPT/Inf (2015) 1), January 2015 – see paragraph 3 and, under “Juveniles deprived of their liberty under criminal legislation”, paragraphs 98 and 99). THE LAW I. ALLEGED VIOLATION OF ARTICLE 3 OF THE CONVENTION 54. The applicants alleged that police officers had slapped them in the face while they were in the Saint-Josse-ten-Noode police station. They claimed to have been victims of degrading treatment. They further complained that the investigation into their complaints had been ineffective, incomplete, biased and excessively long. They relied on Articles 3, 6 § 1 and 13 of the Convention, the first of which reads as follows: “No one shall be subjected to torture or to inhuman or degrading treatment or punishment.” 55. Reiterating that the Court was master of the characterisation to be given in law to the facts of the case and finding that these complaints covered the same ground, the Chamber found it appropriate to examine the applicants’ allegations solely under Article 3 of the Convention. The Grand Chamber agrees with this approach. It will therefore proceed in the same manner. A. The Chamber judgment 56. In its judgment the Chamber referred to the principles emerging from the Court’s case-law on Article 3 of the Convention. It referred in particular to the principle that where the events in issue lay wholly, or in large part, within the exclusive knowledge of the authorities, as in the case of persons within their control in custody, strong presumptions of fact would arise in respect of injuries occurring during such detention. It was then for the Government to provide a satisfactory and convincing explanation by producing evidence establishing facts which cast doubt on the account of events given by the victim. The Chamber also referred to the principle that where an individual was deprived of liberty or, more generally, was confronted with law-enforcement officers, any recourse to