I've developed a couple of theories during this episode:
1.) Boy in the attic may have been locked up there by his parents. Both of whom are miss completely... I kinda connect this to another theory I came up with. At the point where Lee is talking to Kenny and Ben after the sewers, the picture of the guy behind him looks like te zombie from the bell scene. Anyway I think the kid's parents' left him there to die to go to Crawford.
2.) Bell zombie if the leader of Crawford. I am probablly wrong on this. I think that zombie is somehow related to the kid in the attic. I think the zombie's picture is in the kid's house. It can be seen when Lee is talking to Kenny and Ben after the sewers.
3.) Molly was sleeping the doctor when she was in Crawford for med. If players watch the third tape, it starts out with the doc zipping up his zipper. Then turning around and Molly straightening/ putting her shirt (maybe)