A/HRC/39/46 3. Public policies to develop towards an effective investigation 66. The thematic study will also focus on the public policies to implement the obligation to investigate based on the accumulated experience of the Working Group during its 38 years of existence. 67. The State obligation to include enforced disappearances as an autonomous crime (see A/HRC/13/31, para. 649), as provided for in article 3 of the Declaration, appears essential for an effective investigation, as it allows the investigative authorities to understand the specific nature of the crime and the different investigative skills required, which are different from other crimes usually associated with enforced disappearances, such as kidnapping, torture, extrajudicial execution and arbitrary detention. 68. Criminalization of enforced disappearances is also directly linked with the need to design special investigative and prosecutorial units, as have been developed recently in many States. The creation of these units allows cases to be investigated jointly and with a context perspective, rather than investigating them separately. Special units are usually staffed by professionals from different disciplines, such as anthropology, forensic science, psychology and information and communication technology, rather than only lawyers. This holistic approach to investigation allows a better strategy for the prioritization of cases and better use of new investigative techniques, including assessment of scientific evidence. 69. Another element that will be addressed in the study relates to one of the main obstacles to an effective investigation of cases of enforced disappearances, notably the recurrent threats against the complainant, relatives, witnesses, lawyers, human rights defenders, journalists and often also the authorities in charge of the investigation. An effective policy to investigate enforced disappearances is possible only when adequate State resources are available to protect any person involved in the investigation. 70. Security for those involved in the investigations is also essential in order to create an environment in which it is possible for family members and civil society to document cases, which often produces effective results, even if this should not replace the obligations of the State. 71. It is also of the utmost importance that the authorities in charge of the investigation be allowed to access all the archives in which the relevant information could be found. This should be accompanied by appropriate policies for the preservation and disclosure of archives. 72. The lack of professional and independent forensic institutions has also been an obstacle in many cases. That is why there is a need to guarantee the development of local forensic teams that can deal with the challenges that this complex crime entail. 73. Coordination between State agencies is another essential element for effective investigations, better administration of limited resources, clear accountability and the necessary exchange of information among those involved in the investigation. 74. In the study, the working Group will also deal with how enforced disappearances have been investigated in the context of transitional justice and analyse the development of the different schemes in terms of full reparation to victims in the light of the experience of the Working Group. 75. Lastly, the Working Group will study how investigations should be carried out when the victims are exposed to situations of vulnerability, such as is often the case with children, women, migrants, human rights defenders, indigenous people and social leaders, among others. 4. Effective investigation and full reparation 76. As mentioned above, an effective investigation is indispensable in guaranteeing the right of victims to know the truth. As defined by the Working Group in its general comment on the right to truth in relation to enforced disappearance, the right to the truth means the right to know about the progress and results of an investigation, the fate or whereabouts of the disappeared persons, and the circumstances of the disappearances, and the identity of the perpetrator(s) (see A/HRC/16/48, p. 14, para. 1). 10