Interesting or Disturbing?

Working on my research paper i have learned some interesting but mostly disturbing things. The disturbing would be the parts where it tellls about killing some of the disabled people and the children. The ways that they killed were kind of both interesting and disturbing because its hard for me to think of how some one could do that to another person just for the fun of it. Its interesting to think of how one person could hate an entire population of people without them doing anything wrong to him to begin with.