My girlfriend's theory is that Devlin likes little boys and Hornbeck was growing into a young man, less likely to be controlled by threats and abuse. That's why the 11 year old was kidnapped last week and Devlin was going to "dispose" of Hornbeck.
Hornbeck was 11 when he was kidnapped almost 4 1/2 years ago. The other boy, Ben Ownby is 13