This exact situation happened to my family. Wife’s vehicle was left unlocked and property was stolen. Everything was recorded by video and a timeline was established with the help of other neighbors videos as well. Police were notified, reports taken, end result nothing. The question presented by OP was my conundrum also. What can one do to stop the burglary? Deterrents can help like motion activated lights but most criminals ignore them knowing they are automated. (They didn’t care about our lights being on) What you need is to be notified at that moment something is happening. There are some companies that make a motion activated light with camera, two way communication capabilities and an audible alarm that will notify you on your phone as soon as motion is detected. That will give you some choices in the instant the situation arises. THAT is the game changer in this scenario. The second idea I came up with if you really want to pursue the situation is to use a small GPS tracker and place it inconspicuously on a easily identifiable item you own. Make sure you can identify said item by Model# and Serial# or by an engraving with name on it. If and when item is stolen you then have the means to notify the proper authorities immediately and how to locate said item. This in my opinion is the only way this situation can be handled without placing ones self in danger of physical harm or judicial penalty. Of course there could be 1000 different other ways but this is what i came up with.