Hey there....I stumbled across this site last night and have been reading all your posts and thought I would share some of my own thoughts.
This case had intrigued me. So many questions and theories.
I think that someone else was involved in the murder, but not actually in the house with him. Possibly waiting in the car for him or dropped him off and picked him up again. This could have been where the witness saw the 2 males in the 4WD?
And it was said over and over again by police that if anyone has seen someone with scratches/cuts/marks on their arms or hands should be reported to crimestoppers straight away. How did anyone not notice? Surely they weren't small marks if there was enough blood at the house to get a DNA sample from. But possibly, the work college who took him in, noticed these marks and suspected him?
I read all Chantelle's and {mod edit} comments on Bebo. Admittedly, I think she flirted with him somewhat. Maybe that was her nice nature, but I think he may have taken it as flirting. Possibly he went to the party and after a long time of being friends with her (I say that because their Bebo comments were dated back to last year I believe?), and plucked the courage to finally make an advance at her, and she turned him down? I can imagine that would have pissed him off! He mentions on his Bebo that he has been raised by only his mum since he was 2 months old. Rejection and abandoment issues? But surely she would have told atleast one of her closest friends about it though? And they would have passed on that info to the police immediately after the murder? One would think anyways. But I have a feeling police had him as a very vague suspect to begin with, or at least a few days before they actually arrested him.
As for the murders, there's a few theories. Possibly he killed the parents first so he could spend more time on Chantelle. (That sounds so horrible!)
You would think though, that if she was hiding in the closet, she would have grabbed her phone and called police? I know I would have! It would have take a good few minutes to kill the parents, that would have given her enough time.
Or maybe, he attended the party the night before and realised her parents her away (I read a report that her parents were staying with friends in Adelaide on the Saturday night), and he assumed she was still home alone? The parents being there startled him and he killed them as well? Another possibility.
Did anyone see the comment he left on the Chantelle's facebook tribute page? How creepy can you get! I read them all but didn't know his name at the time, then by the time I found out his name, the comment was deleted. But also his fb profile being deleted probably removed the comment anyways. Maybe he was totally schizo, and made himself believe he didn't do it....with the message on her tribute page, and going to her shrine. CREEPY!
Can't wait until he admits to it and more details are released!
Sorry for such a long post!