affect men and women differently. Depending on the source and type of information, the commission/mission will have to determine who has the information and what method will be used to collect it. (a) Victims and witnesses The testimony of victims and witnesses constitutes the most valuable information available to the investigation. Apart from those who experienced the events firsthand, there may also be other observers of situations who could provide important information, including local officials, staff of United Nations and international agencies, United Nations peacekeepers, diplomats, refugees and displaced persons, community and religious leaders. These observers may be able to provide information about the context in which the incident under investigation occurred and what events preceded and followed it. They may also be able to provide information to corroborate the testimony of victims and witnesses. (b) Alleged perpetrators Alleged perpetrators could be a rich source of insider information that is often difficult to access. Considerable information is provided publicly by alleged perpetrators who often use the media as a propaganda tool, boasting about their achievements. In some instances, alleged perpetrators may be willing to disclose information about violations committed by others in their groups because they disagree with such actions or to divert attention from themselves. Alleged perpetrators may also be willing to provide information on the hierarchy and command structure of the entities involved in the violations, and may be able to provide documents or other materials (for example, video) to corroborate their stories. The International Commission of Inquiry on Libya interviewed several senior officials of the Qhadafi regime in custody who provided information on specific incidents, the different entities in the security forces and their command structures. Some also corroborated information gathered from victims and witnesses. Investigators should be cautious about accepting at face value anything that an alleged perpetrator says and, similar to information provided by others, should find other sources to corroborate the information. Additionally, they should be cautious about the person misleading the investigation and diverting attention away from the incidents being investigated. GUIDANCE AND PRACTICE 43