LLM / Department of Public Law / Since the birth of international criminal justice, the imposition of individual criminal responsibility has been expanded as evidenced by the instruments establishing the institutional mechanisms, at least, from Nuremberg to the Rome Statute of the International Criminal Court. The prescriptions of the imposition of criminal responsibility in international criminal law take cognizance of the fact that both top civilian and military personnel commit heinous crimes. However, until the establishment of the International Criminal Tribunal of Rwanda (ICTR), such prescriptions covering individuals who find themselves within informal civilian relationships had not earned much focus, be it at the identification of responsible individuals to their prosecution and conviction. Events in Rwanda during the 1994 genocide that led to the establishment of the ICTR revealed the involvement of this category of individuals. While their involvement took diverse forms, at different times, only some of them were identified and successfully prosecuted and convicted for the offences over which the ICTR has jurisdiction. This category of individuals (those falling under the rubric of informal civilian relationships) has not been addressed by scholarship on international crimes. This dissertation identifies such individuals, examines the allegations against them, the factual findings of the different Trial Chambers and develops a set of rules as well as lessons to be learnt from the trial and appellate proceedings