The old-fashioned but very effective system in UK years ago was: "bobbies on the beat!" and much more effective than "Bobbies sitting in the Office" all day! Unfortunately, not much prevention, only around later to pick up the pieces!
Amazing what on-the-ground observations about many aspects matters untoward can be made, especially in areas prone to such things:
Pattaya and Phuket spring to mind as areas of greatest need!