G'day Justine, you should not have any trouble continuing in the same job in Perth, it is after all a growth industry.
The Australian legal system and therefore the Courts System is based on the British and you would find no problem.
In so far as cities go, Perth has a relatively low crime rate.
In any case, who knows what you might end up doing, Western Australia Police is on a big recruiting campaign, are you interested? :)
All the best and good luck.
Cheers.