I think Jimmy's been helping the sheriff tracking JW. My guess is it's Henry.
im actually hoping that henry is in fact wakefields son. it look like he shouldnt be a suspect but he has done some things that seem to help wakefield out in the long run. what i dont get is why wakefield would honor the sheriff's deal once he was dead. if wakefield wanted to kill everyone on the island jimmy would have been the easiest target, after the sheriff was dead of course. and Scoobybug, why would wakefield want jimmy to get so close to abby, if he knew they were half brother and sister. it doesnt make sense. i was surprised henry didnt get shot at when he was in the wide open door of the cannery waiting for the cocktails to be lit. wakefield had an clear shot. so ya jimmy and henry are my two suspects.