Lacy Wood said:(snip)
There are undoubtably other scenarios. I personally hope one shows up exonerating the family, but you can't rule them out on a clean past or religious factors. Every existing offender had a first time and how many times have we heard about the Sunday School teacher or even preacher who blew away his wife?
Ted Bundy got away with nearly 'perfect' murders for quite some time and was almost ruled out of the suspect pool because he was a law student with no criminal history.
Please understand I am not saying the killer of JonBenet was a serial killer. Rather, I am saying crimes are committed in which very little forensic evidence is discovered and when such forensic evidence is found, it doesn't stand up and shout the name of the person.
You are correct in stating every offender has a first offense, but generally there is some record of such; unruliness in school: temper tantrums; harming children or animals, etc. In other words, there is a behavioral history leading up to the first offense.
As for Sunday school teachers and preachers who blew away their wives--look to their history. Not just behavioral, but also financial, social, work related, a personal disappointment, drug or alcohol problem, or mental illness. Those people whom others believe 'simply snap' have had onging difficulties in some area of their life and if LE looks, they will find it.
Why didn't the killer take the body with him? Unless he was into necrophilia, why would he want to burden himself with disposing of a corpse?
Rainsong