Despite coming from a typical healthy family, Robin Westman's horrific decision to shoot up a Minneapolis church full of children was inspired by online terror groups who exploit young people.

It's difficult to imagine a more horrific crime than killing children as they pray in church, so it will be a particular challenge trying to understand the sort of person prepared…

Robin Westman once attended the same school as the victims and was ‘obsessed’ with the idea of killing children, authorities say.