He loves talking about things like this, and loves that Kate is asking him about them. Most people would just think that he's morbid and change the subject.

"It stems from wanting to keep something, to hold on to it. Maybe they experienced some kind of loss that affected them deeply," Malcolm says. "Sometimes it also has to do with protection, but mostly it's possession. Dahmer tried to do the same thing with his victims when he tried to turn them into zombies."