We have lots of opportunistic burglaries in some areas here (not where I live luckily). It is a common saying that the best deterrents are your neighbors / your community.
People actually tell each other when some new guy shows up and is lurking around the neighborhood. There is also some sort of community spirit so that even in major cities each street has something like a headman and sometimes they also have speakers hung up and the headman makes announcements whats going on (and plays awful music for a few minutes before he makes that announcement).
Smaller towns and villages also have headman who really run the place (along with the local cops and military if its in the area). This is a very old fashioned way of living but it really works and prevents a lot of crime from happening.
Alea iacta est ("The die has been cast")