Churches seem to be a popular target for disturbed individuals these days. They, like schools, are gathering spots for innocent people who are unarmed and are lambs ready for slaughter. There is also the, "My God is better than your God syndrome" to deal with. If you go back in history, you find there is a religious aspect to almost every war. Of course the study of history is not something that our schools feel is important to teach these days.
There are also political factors to consider too. In my humble opinion, there are political conspiracies involved in most of these shooting.There is one political factor trying to make the other look bad. Then there are those who try to make things like Gun Control look enticing to the general and uninformed and poorly educated masses.