That was a big fat fail

First off, I don't know what the zoning laws are where you live but in a lot of places electric fences and razor wire are prohibited. Secondly, some police departments will not prosecute people for trespassing unless the property is posted no trespassing. So my suggestion, post the property in multiple locations so no one can claim "I didn't see the signs". Install good security cameras with storage capability. The first time someone ends up on candid camera, make a trip to the cop shop and make an example of him/her. The old saying about shooting the first one and the rest will fall in line has some truth to it.