So, I am going to propose that in addition to his clearly stated white supremacist racism and desire for race war to erupt as a result of his shootings in the Emmanuel A.M.E. Church in Charleston, the possibly drug-crazed shooter may also have had a more specific goal, even if it was just secondary to his broader desire for a race war. That he had very carefully selected his main target, the Rev. Pinckney of that church. So, rather than being some sort of random "domestic terrorism" or just generally insane shooting up some movie theater audience, he had targeted this particular man in this particular church. After all, he supposedly had been plotting something along these lines for at least six months.
It now appears that Rev. Pinckney may have been the leading political figure of the entire South Carolina African-American community. He had served in the state senate for 15 years, and he had just gotten a lot of publicity for an eloquent speech made in the wake of the shooting in the back of a black man in North Charleston by a policeman. Roof was known to have ranted about Trayvon Martin and other such cases, so one can imagine that this particular case where pretty much even the usual defenders of white police killing black people were appalled and said that this cop should go would have upset our Mr. Roof. One can imagine that his obsessions and hatred could easily have focused on this eloquent speaker and leader, minister at a famous and historic black church.
Now, it is possible that Roof really did not know whom he was shooting other than that they were a bunch of black people in a Bible study group in a church. But, although it cannot be proven, and as I admit, he has not been reported to have made any remarks about Pinckney, it is highly likely that he knew exactly whom he was shooting and who was leading that Bible study group. It is curious that there is a report that he hesitated, due to their being "so nice" to him. That family members of some of the victims have forgiven him says a very great deal.
But, I think that we should consider it likely that this was a targeted political assassination, in addition to all the other things it is or has been.