After a 211 Crew parolee killed Colorado prisons chief Tom Clements in 2013, officials began banishing leaders of the white supremacist gang to prisons across the U.S. through an inmate-swapping system in which high-risk prisoners are secretly traded from one state to the next, The Denver Post has learned. That diaspora of shot callers, those who can order gang murders, is why Benjamin Davis was at the Wyoming State Penitentiary south of Rawlings when he killed himself last month.