For HRDs and experts: Investigative bodies generally seek out primary sources, i.e., those who saw or suffered an incident first-hand. While it may be that a given HRD is also a victim of or witness to specific violations – and if so should be interviewed as such, they can be key secondary sources, given their front-line position and close contact with the communities affected. HRDs may serve as intermediaries between the investigators and victims and witnesses. With regard to the practice of identifying individuals, they may be helpful with actor mapping, will probably be aware of the main events and crimes, and may have an analysis that assists the investigation in understanding the context and background – and thus the motivation – of various individuals or entities that might have committed violations. Investigators should also seek to understand the methodology the HRDs apply in their work. Interviews with HRDs should focus on: • Their knowledge of major events/incidents/attacks/treatment and who the victims or responsible parties may have been; Thousands of civilians march on the 17th anniversary of the Santa Cruz massacre in Timor-Leste. UN Photo / Martine Perret 64 ATTRIBUTING INDIVIDUAL RESPONSIBILITY