A Theory for Harper's Island: Henry=Killer?

I have been thinking for some time now that it could be Henry. I agree with you that there's no way it can be the sheriff, especially with his leg. As for Henry, he's always conveniently around when they found the bodies. But he's always "missing" before the crimes are committed. Also, how did he get all of those cuts on his arm. He never did explain it. I think JD was trying to fight back and attacked Henry, which is how he cut his arms all cut up.