The Working Group has for decades brought the issue of structural impunity for enforced disappearance to the attention of the international community. In 1993, following consultations with States, relatives of the disappeared and civil society organizations, it issued a report outlining recommendations aimed at ensuring accountability and preventing impunity for acts of enforced disappearance. The Working Group has repeatedly underscored that an effective criminal investigation is crucial not only for upholding the right to justice, but also to fulfilling the obligation to search for the disappeared person and for the enjoyment of the right to the truth and reparation, as these rights are closely intertwined. Nevertheless, the Working Group continues to observe reluctance when it comes to the diligent investigation of all allegations of disappearances and the holding of their perpetrators to account. Even within contexts where there is political will to tackle impunity and address cases of enforced disappearance (mostly in transitional processes), the limited availability of institutional instruments often represents an obstacle to their completion. The present report is aimed at identifying the principal elements necessary for the design and implementation of investigative standards and relevant public policies in order to more effectively investigate cases of enforced disappearance and bring their perpetrators to justice. Challenges and good practices will also be analysed.