I was curious so earlier today I sat down to listen to the walking dead soundtrack on youtube. The majority of the songs were the ones used in the ends of various episodes from season 3, but this one in particular (link to it below) made me perk up because (firstly) I recognized the band who preformed the song, and secondly, about 30 seconds in, I realized what an amazing song it was. Really captures the mood of TWD when major deaths occur. So then I realized, this song wasn't used at all in the show (at least I'm pretty sure it wasn't), so whats the deal? I think it would've been the perfect song to play in the background during Andrea's death scene, or after Daryl found Merle, or hell, even during Lori's death.
Take a look-see and decide for yourselves: http://www.youtube.com/watch?v=EtlXkNXms4A