I don't know how someone would be shocked over this quite frankly, we all know racism hasn't gone away. We know that there still is a great hatred for African Americans/minorities by some whites and that some of them are willing to kill because of it.
As I've said on this board before I believe we are tightly enveloped in mental slavery and until we break the chains we will still be seeing things like this and racism/acts of hatred & violence will continue, and it will get worse.