Out of all the ways Lee could've taken him out the picture, killing him seems way too over the top. If he was ready to do that, why not just kill Belinda earlier?

So let's look at the other suspects:

the crazy teacher he was sleeping with (my first thought)
Belinda (couldn'tve been her based on the body shape of the shooter, but she could've hired somebody...maybe the guy from ep 2)
Ray
Bill Hayden
Lee's neighbor (didn't look big enough to me though)
Bill Motherfucking Murray
the horse man (shit shoveler)

My guess is Belinda's guy or Ray, but part of the fun will be Gamby trying to figure it all out, and I'm sure he'll trust no one. Also wonder when Will Ferrell will make his appearance, I thought he might show up in the finale as the new principal.

Pretty good season, but this show should be judged as a whole after season 2. Hope it returns early 2017, considering it's all been shot already.