Mohammed Yusuf
a Salafist Islamic cleric who founded Boko Haram with the goal of creating an Islamic state to replace the secular Nigerian government. Boko Haram, originally nonviolent, grew out of Yusuf’s religious school in northern Nigeria. In 2009, Yusuf died while in police custody, and his death, suspected to have been an extrajudicial killing, radicalized Boko Haram, which reemerged in 2011 as a violent extremist group.