Ohhhh man, that's -- it's a whole story.

[He tries to think how to answer, how to phrase it as diplomatically as possible, given the investigation still going on back home.]

Essentially, there was one serial killer, this guy John Kramer. He had disciples who ended up taking over his work when he died. And there were several of them, so it wasn't easy to nab all of them.

And then at least one other serial killer seems like he was inspired by him, even if he might not have actually met him.