70. The purposes of witness interviews are to: (a) Obtain as much relevant information as possible, through a systematic and fair process, to assist the investigators in objectively establishing the truth (b) Identify possible suspects (c) Allow individuals an opportunity to provide information that they believe is relevant to establishing the facts (d) Identify further witnesses (e) Identify victims (f) Establish the location of crime scenes and burial sites (g) Establish background information and facts relevant to the alleged killing(s),94 and (h) Identify leads in the investigation. 71. Investigators conducting interviews should approach all witnesses with an open mind and observe the highest ethical standards. A careful assessment of risk, strategies and adequate human and financial resources must be in place to ensure the safety and security of all witnesses in the case. Families in some circumstances could, with reason, fear for their safety. Careful attention should also be paid to the safety of the investigator, since a witness may be the perpetrator. 72. A list of significant witnesses should be drawn up and their interviews prioritized. These witnesses include those who saw or heard the crime being committed, people with relevant knowledge of the victim(s) and/or suspected perpetrator(s), and people in the same organization or chain of command as the suspected perpetrator who may be able to provide information linking people other than the direct perpetrator to the death.95 Full statements should be taken from these witnesses. Where feasible and appropriately secure, investigators should consider recording their interviews by audio or video means. During the investigation phase, witness lists are highly sensitive and must be carefully safeguarded to ensure that witnesses are not exposed to undue risk. Electronic documents that may identify a witness should be taken outside the investigation office only in encrypted form. Access to hardcopy documents that may identify a witness must be restricted to the maximum extent possible. 16 73. House-to-house inquiries should be conducted in the vicinity of important physical locations and the crime scene, if it has been identified. Houseto-house inquiries help the investigators to identify witnesses who live or work in key areas, gather local information and intelligence, identify other witnesses or suspects and raise awareness of the investigation, which may encourage people with information to come forward. 74. Interviews with family members and others to collect ante-mortem data for body identification – such as hair, blood, saliva samples, dental or chest X-rays, and information about possible bone fractures and other injuries or diseases – should be conducted by trained professionals who are in a position to answer technical questions authoritatively and with at least a basic knowledge of the correct medical and odontological terms. Proper equipment is needed to take samples, and donors should complete consent forms that state how the samples will be stored, who can access them, who manages the genetic database and how the data is to be used. 75. A media appeal may help to identify and locate people and material that could be useful to the investigation. This could include setting up a telephone hotline, an email address and/or a social media web page, which people could use for providing information to investigators confidentially or even anonymously. Consideration should also be given to offering a reward in return for relevant information. 76. A specific strategy should be developed, especially if a suspect is a state official, to ensure that anyone coming forward will be assured that the information they provide will be dealt with confidentially, within the limits of the law. 6. International technical assistance 77. The assistance of law enforcement agencies in other States may help the investigation cover any gaps in the technical capacity of local investigators. International bodies such as Interpol, for example, might be able to support the investigation, and humanitarian organizations such as the International Committee of the Red Cross (ICRC) might offer advice on forensic best practices for the proper and dignified management and identification of the dead in humanitarian contexts. 94 This may include, for example: the identity of political officials or military and paramilitary leaders; the identity and description of perpetrators; chains of command; communication codes and methods; details of official documentation linked to the killings; public announcements relevant to the crimes; interaction between military and political structures; the financing of military operations; and the chronology of events leading up to the killing(s). 95 For example, this could be through various modes of liability, including participation in a joint criminal enterprise, superior responsibility, ordering, aiding and abetting, planning, or instigating. The Minnesota Protocol on the Investigation of Potentially Unlawful Death (2016)