preventive measures.EXPATS UNITE!
As it is almost certain this was a job by people who came to work at the house(my priviliged information),i wonder about the following:
What about it if all expats would demand contractors to provide them with a list of workers and a copy of their KTP?
And make this known to all their workers,so it has a deterrent effect.
It is unlikely contractors do a check on criminal records on the workers they send in,many of them coming and going and only staying for a certain period of time.This way the workers would be less anonymous,and the police could check them out,albeit after the fact.
I am especially thinking about contract work like people who tend your garden,build pools,bale's,or even your new house.
if a contractor does not want to cooperate,too bad,he should not be given the job if your security is not his concern.
Most cases of robbery you read about in the indonesian language papers involve someone who is familiar with the house.
Time for an expat union to make a fist?Expats of all nations,unite!
About the perimeter:If it would be impossible to make a quick getaway,it might also scare people off.So if you have an electric opening fence,that is operated from the inside ,it might be a good idea to close it with a visible chain and padlock at night.