Origins of Hutu, Tutsi and Twa of neighboring people, it was almost non-existent among Rwandan Tutsi. Presence of the sickle cell trait is evidence of survival in the presence of malaria over many centuries, suggesting differing origins. Regional studies of the ability to digest lactose are also supportive. The ability to digest lactose among adults is widespread only among desert-dwelling nomadic groups that have depended upon milk for millennia. Three quarters of the adult Tutsi of Rwanda and Burundi have a high ability to digest lactose, while only 5% of the adults of the neighboring Shi people of eastern Congo can. Among Hutu, one in three
Rwandan genocide between Hutu, Tutsi, and Twa. The systematic destruction of the judicial system during the genocide and civil war was a major problem. After the genocide, over one million people were potentially culpable for a role in the genocide, nearly one-fifth of the population remaining after the summer of 1994. After the genocide, the RPF pursued a policy of mass arrests for the genocide, jailing over 100,000 in the two years after the genocide. The pace of arrests overwhelmed the physical capacity of the Rwandan prison system, leading to what Amnesty International deemed "cruel, inhuman, or degrading treatment". The country's nineteen