I'm not sure how you can say making Cohle the current killer is "dumb".
Maybe something you don't like, but it's not dumb. It's set-up, foreshadowed, and plausible.
I agree that if they all the sudden do something like Marty is a member of a satanic cult and he is going to sacrifice his oldest daughter, that would be "dumb," because it would go against everything we know about the character and it would have no foreshadowing or set-up to it. It'd just be a cheap trick by the writer.
There wouldn't be anything "cheap" about making Cohle some type of psychopath, because whether he is killing or not, he is clearly not "right".
Reminds me of earlier in the thread when people were speaking in absolutes saying the cops didn't suspect Cohle as the killer and the writer wasn't trying to make it look that way. Just a complete misread on the show by some.
BTW, right now I don't think Cohle is the killer, either, just saying it wouldn't be "dumb" if he was, in my opinion.
[This message has been edited by bendover (edited 2/17/2014 8:43p).]