This discussion may contain spoilers!
After episode 2, i feel more sure than ever.
The fact that the victims were people that Crane used, hint that the killer is trying to fuck with Crane.
And who's Crane's Top Nemesis?
Well the Horseman of course.
Add to that the fact that all the murders so far have been decapitations.
It well may be that he's working with someone, someone who told him to "stop laughing".
But without no mouth to speak with, there is no sound.