Murderers are the same as you and me, subject to gravity, time, weather.. the earth goes round the sun for them the same as it does for me ... time doesn't speed up , or slow down just because you are killing someone.. the clock ticks on relentlessly, if it's winter, the days are short, if it's summer the nights are short, a murderer gets no special dispensation..
Working backwards from Karen's burial location. .. the science of geographical profiling comes into play.. this was a particular branch of criminal profiling entered into in the aftermath of the Yorkshire ripper killings.. invented by a scientist who was a former RAF navigator in the 2nd world war..
He had to get his plane to the target, and get it home, to base within a time frame, crossing degrees of longitude, and latitude, racing the sun home, and flying towards it on the way out, but always with the home base clock ticking on a inflexible path.
What has this to do with Karen, in particular? .. Every crime has a home base. That is, every criminal has a place he/she calls home, and it is from this home that he/she ventures out, commits the crime, and returns back to base.. Even if the crime is committed in the home base itself, rooms have to be navigated, but more importantly, time has to be managed and apportioned to each task that must be achieved..
It is reasonable to assume that Karen's location of burial had to be in proximity to the killer's. This killer was burdened by time problems. He/she cannot drive the body over to South Australia and leave it buried in the desert, or take it up to the Murray River and leave it between Mildura and Renmark, far , far away from any hint of the original leaving place, Avondale.
Time has compelled this killer to do the quickest run he/she can. That means highway travel, but even then, time relentlessly rolled on, and the time taken on the out trip has eaten into the time left for the return trip.. There is only so much time to get rid of the body ( evidence) . and the sun comes up on another day, as usual, the dawn doesn't delay to assist a killer. ..
Geographically, taking into account where Karen lived, and where her reasonably suspected killer lives, and how much time in the normal day is possible to maintain a façade AND bury a body as far away from the home , in the winter, and subconsciously travelling in a direction already well known * ( Son at Diggers Rest, Brother at Toolern Vale, and in a time of stress one clings to the familiar )Mt Macedon is just about right on the money.
