'The Devil' was a Tutsi
http://en.wikipedia.org/wiki/Robert_Kajuga
Robert Kajuga, 'the devil' from the book's title whom Dallaire said had dried blood on his person as he shook his hand, was leader of the Interahamwe. He also was a Tutsi.
Interamhwe was Hutu, not Tutsi...
... but its director was Tutsi!
See http://en.wikipedia.org/wiki/Interahamwe