18 84 against women and the willingness to act immediately. Above all, it is essential that police authorities, prosecutors and judicial officials take prompt action by ordering, without delay, the necessary measures 85 to determine the whereabouts of the victims or the place where they may have been retained. Adequate procedures should be in place for reporting disappearances, which should result in an immediate effective investigation. The authorities should presume that the disappeared person has been 86 deprived of liberty and is still alive until there is no longer any uncertainty about her fate. 81. The IACHR has also established that in cases involving violence against children, the 87 State’s duty to protect the right to life is particularly strict. This stems, on the one hand, from the broadly-recognized international obligation to provide special protection to children, due to their physical 88 and emotional development. On the other, it is linked to the international recognition that the due diligence duty of States to protect and prevent violence has special connotations in the case of women, 89 due to the discrimination they have historically faced as a group. In other words, the State had an enhanced duty to protect the rights of María Isabel Véliz Franco because of her condition as a minor, and 90 an obligation to adopt special measures of protection, prevention and guarantee. 82. The Court, for its part, held that the State must pay special attention to the needs and rights of victims who are girls who, as women, belong to a vulnerable group. It therefore concluded that that the State has the obligation to adopt all positive measures necessary to ensure the rights of 91 disappeared girls. Specifically, the State has the obligation to ensure that missing girls are found as soon as possible, once the next of kin has reported that they are missing. Accordingly, it must set in motion all resources to mobilize the different institutions and to deploy domestic mechanisms to obtain information in order to locate the girls rapidly and, once their bodies are found, to conduct the 92 investigations, and prosecute and punish those responsible effectively and promptly. 83. The United Nations Special Rapporteur on violence against women has written that based on the precedents forthcoming from the inter-American, European and universal human rights systems, and “on the basis of the practice and opinio juris […], it can be concluded that there is a rule of customary international law that obliges States to prevent and respond to acts of violence against women 93 with due diligence.” 84 I/A Court H.R., Case of González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205, paragraph 285. 85 I/A Court H.R., Case of González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205, paragraph 283. 86 I/A Court H.R. Case of González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205, paragraph 283. 87 IACHR, Report No. 80/11, Case 12.626, Jessica Lenahan (Gonzales) et al. (United States), July 21, 2011, paragraph 129. See, IACHR, Report No.28/07, Cases 12.496-12.498, Claudia Ivette Gonzalez et al. (Mexico), March 9, 2007, paragraphs 247255; I/A Court H.R. Case González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205, paragraph 245. 88 IACHR, Report No. 80/11, Case 12.626, Jessica Lenahan (Gonzales) et al. (United States), July 21, 2011, paragraph 89 IACHR, Report No. 80/11, Case 12.626, Jessica Lenahan (Gonzales) et al. (United States), July 21, 2011, paragraph 129. 129. 90 IACHR, Report No. 28/07, Cases 12.496-12.498, Claudia Ivette Gonzalez et al. (Mexico), March 9, 2007, paragraphs 247-255; I/A Court H.R. Case of González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205, paragraph 403. 91 I/A Court H.R. Case of González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205, paragraphs 408- 409. 92 I/A Court H.R. Case of González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205, paragraph 410. 93 Integration of the Human Rights of Women and the Gender Perspective: Violence against Women. The Due Diligence Standard as a Tool for the Elimination of Violence against Women. Report of the Special Rapporteur on violence against women, its causes and consequences, Yakin Ertürk. E/CN.4/2006/61, 2006, paragraph 29.