One Hutu killer describes feeling “like two different people” as he took part in the genocide: a man who obediently slaughtered his Tutsi neighbours because the mayor told him to, yet who hid one of their daughters in a grain basket to save her from the machetes.

A Tutsi survivor recalls the moment attackers rounded on her 17-year-old brother as he cried: “Why are you killing us? We used to be friends.”

And an aid worker and an ambassador lament the world’s failure to stop the fastest genocide of its scale in history.

These are fragments from a series of first-person accounts we’ve collected to mark the 20th anniversary of Rwanda’s 100 days of slaughter. Taken together, they give extraordinary insight into the psychology of atrocity: how so many ordinary people – friends, neighbours, doctors, teachers, priests – could take part in the bloodletting.

They also hint at the moral complexity underlying Rwanda’s efforts to balance truth and reconciliation, justice and forgiveness.