This discussion may contain spoilers!
In the last episode of season one, you have a choice to kill Lee or let him turn into one of the dead. If you choose to kill Lee you see Clem aim, turn her head, close her eyes, and shoots. When the bullet if fired you don't really hear any impact and when the screen goes black you here a gasp of air.
Now I have read the comics and have watched the TV show, but maybe there is a walker who is half human and half walker. Tell me what you think about this and also tell me if it is possible to be half human and half walker.