as ole kelly said and as hulud agreed a true christian would never do such a thing...
but it does exist... there are so many who use the excuse "God told me to do it" or "It was God's will that i destroy all those people/buildings" but normally those people are crazy and have very crazy tendencies.... in my opinion they are probably being attacked by some very strong demons who talk them into doing these things, making them think it's ok and that's what God wants them to do...