(b) Perpetrator-targeted questioning Investigation practice is generally to prioritize first-hand information.107 A wellinformed and well-prepared investigator – one with an in-depth understanding of the relevant events, organizational structures, individuals and elements that have been established and those that are outstanding – can secure valuable information from interviewees. In preparing for interviews, questions should be devised that aim not only at the identity of the person(s) believed responsible for the incident(s), but also all the other elements required to prove responsibility, such as – for international crimes – the mode of liability or mens rea. At a minimum, questions should cover: For victims and witnesses to incidents: • Whether the interviewee has information as to who (individual or unit) might have been involved; who might have ordered the attack/arrest/treatment. (Names or nicknames, etc.) • Whether they can describe the individuals, including how many were involved. - Physical description (approximate age, height, hair colour, unique features, tattoos) - Ethnic group - Uniform (colour/design), if any, or dress/civilian clothes and any distinctive emblems or insignia - Rank(s), if identifiable - Types of vehicles, modes of transport (insignia, licence plates) - Types of weapons - Languages, dialects spoken, accents - Location (current or usual base/camp) • Who seemed to take charge during the incident/attack? Were any instructions given? If so, by whom? • Can they identify the leadership of the forces operating in their area? • If the individual(s) used radios or phones to communicate, what did they say? There are multiple reasons for this, including the imperative of giving a voice to victims of violations and crimes. Other considerations are the ability to evaluate a source more effectively when they are being interviewed one-on-one, the limitations on time and resources confronting most CoIs, and the challenge of evaluating the often vast amounts of open-source material. 107 60 ATTRIBUTING INDIVIDUAL RESPONSIBILITY