I read this article on the Norway shooting
and it shows how planned the perp was. He definity had beliefs of religion and prejudices of people. It looks as though you cannot even be secluded on a secluded island. I don't know how a person or group could sniff out ticking time bombs like this but I know there are a lot that are noticed and ignored. In the Virginia Tech shooting the perp was turned in to the administration more than once for being a threat and yet he was kept in the school. The perp from Fort Hood was promoted away from one facility to another. The undercurrent of law is watch your back jack.