S6·E22 The Soul of Winter

Roscoe Jones, the (black) minister who succeeded Trent's father is being targeted by a man named Stan Gorman. It seems that years ago when Roscoe was in the Army, his friend, who is also black was the C.O. of a unit and one of the men in his command's Gorman. Gorman's a bigot, who didn't like being ordered by a black man. Eventually the tension between the two men reached it's breaking point when Gorman tried to kill Roscoe and his friend, while he killed his friend, Roscoe survived and testified against Gorman, who would be sent to prison. While in prison Gorman became head of a white supremacy group, and now he is after Roscoe.