I'm not sure how your local laws work, but where I am I would have to go to the county magistrate and file criminal charges. At that point, the person who is having charges filed against is served with a summons and a court date. That date is usually just the day where they say they will either defend themselves, get a lawyer or apply for the county lawyer and then a trial date would be set. At the trial, it would basically be your word against his unless you have photos or other documentation showing that he was on the property. It would be up to the judge at that point, though. If he was found guilty, though, and he kept doing it, he'd proly get jail time the next go round. Like I said, I don't know how it works where you are, but thats what I would have to do. It's a big pain and unless you have good proof, it proly won't fly - unless the guy is an idiot and admits to it...