I was always outraged at the media frenzy surrounding this case. The mother was literally hounded to her grave. I have heard, though, that the police were watching and building a case with DNA evidence for several months, and the Ramsey's were informed of this. I believe that Mrs. Ramsey knew before her death that her daughter's killer was about to be apprehended.
The suspect was caught after all this time in Thailand, largely because of his involvement there in the child sex 'tour industry'. Cases like this, and the realities of parole and probation, are reason enough why I have no qualms against the death penalty.
ADDED ON EDIT: As far as children being killed or kidnapped while the parents were asleep in the same house, isn't this exactly what happened in the Lindeberg case?