So lets presume for the sake of argument (notwithstanding legal process) that BRE is the man. ie the sleuthing to find the CSK is complete - thus no real need to keep turning over old ground.
Lets turn our attention to where SS might be.
Lets also remember that very few things in life are "indisputable facts" and that most things are balance of probabilities. So keeping probability in mind...
Probability would indicate he was initially "just" a rapist. He (via the DNA) has demonstrated that he has been "happy" to let a victim go (post rape) ie KK victim. There has been no indication that she escaped. All reporting is that she was let go. If he were a "murderer" / full blown SK why does he let the first one go??
Probability is that SS was a blitz due to the fact that she had called a cab - therefore improbable that she would just grab a lift (within 8 minutes) - also probably not completely falling over drunk as she still had the wherewithal to make the call. A drunk(er) person would probably have hoped to flag a cab down (rather than call), and therefore more likely to accept a lift.
SS was a country kid (father a shearer) and not super petite so she was probably reasonably strong. So BRE grabs her for the purpose of a rape. She fights back a little too well and he then goes over the top and kills her. ie the death is in all probability an accident, and not the primary purpose of the (likely) blitz. Now he has a problem. He has a dead body he needs to get rid of and he is probably pretty panicked, because a "simple" rape that he has done before with success has now gone massively pear shaped. Where do you go and what do you fall back on?
I think in that "stressful" situation probability dictates you fall back on places that you know, but aren't stupidly obvious and problematic (like ones actual backyard). To that end I think you get rid of the body in a place you are deeply familiar with rather than some random place that you likely know less well (eg Eglington and Wellard).
So where is the highest probability place that you know well, that is not as stupid as a backyard, that is suitable for the concealment of a body?
The bushland opposite your parents old place. You would know it like the back of you hand as you probably spent plenty of time in there as a younger kid / man. It is far enough away from your current place (Fountain Way) so as not to be completely obvious (in the same way that there is almost no chance she is in any of the backyards.)
As you can see by the wider view of the attached images (historic from Feb 95 - note north of the map is primarily residential housing in 95 hence not included) it was the heaviest piece of vegetation in the area (other area might be over near corner of Warton and Ranford Roads - Rectangle). I doubt you would use the less vegetated areas as I can't imagine you want someone to drive past and see you with a shovel at 3:30 am. You need the concealment of the vegetation.
The overlay of the map shows where the houses currently are. I don't think she would be under the small northern bit that has been redeveloped as that was done ~2000 and also may have been a little too close to the neighbour with the vineyard / plantation.
So the question is why aren't the cops all over this patch of dirt???
It is a comparatively small (inexpensive to search) piece of ground. It has to be the most probable place for SS to be and even if it turns out she isn't there surely the cost benefit has to be worth a crack. PR win for WAPOL would be massive and would reduce any bargaining for a reduced sentence if they find her without a confession.
