Wow, a little inside look at the psycho, and psycho he is. I guess that rules Nan out, but does Nan have a brother? It seems he has had Hailey in his sights for some time, and now sees the cop, (Brad), as his rival, so what is he going to do about Brad and Star? Very mysterious mystery novel.
Yes, all mysteries narrow as time goes on and characters get ruled out.
Thanks, @bashadow