At the beginning it seems that Eric was the one who kidnapped Bill, and even we have it confirmed "I will take care of Bill Campton personally".That points Eric is guilt, but out of curosity I've read what the third book is all about and I found out that it was not Eric at all.Anyway here is what I know...
Spoiler:
Yeah, if it seems like the obvious choice, it's probably not the right person. At least in True Blood. Not going to click the link though, I want it to be a surprise! lol