I guess I missed something, but to be honest, I wasn't really paying attention after a while. At some point, they just announced who the killer was. I don't recall them saying what led to their suspect being arrested. I suppose I could go back and re-watch it to see what I missed, but I'm not going to. The show is just too boring. I did learn a lot about the porn industry in New York in the 70's. Not that I cared. I still don't know anything about the case. I guess I'll read about it on Wikipedia.