I had a similar problem with trespassers on the 47 acres that I own. Had posted about it in another thread a while back. My property is nearly all woods, and the trespassers were mostly teens from a nearby new neighborhood who decided that my land was a good place to party and have sex. There are a lot of trails and such, and blinds I use for hunting, forts and tree houses that my kids and their friends have built. Have it clearly posted at all trail entrances and several other spots with no trespassing signs. Up until they built this neighborhood, my closest neighbors were about 3/4 mile away, and I never had problems with any of the local kids, they were raised right, respectable. So I knew where these kids were from, but I did not know who they were or what house each one lived at. We gave a nice letter to each family there, but the trespassing continued. We were kind of in a dispute already with some of them over the fact that they did not like that we were shooting our guns a lot. The trespassing continued, so one night I snuck up on them, has my PS90 in hand, and a 1911 on my hip. Asked them politely to leave, that they were trespassing on my property. Did not point either gun at them, explained to them how trespassing could get them shot, but did not threaten them as such. Did not have any problems for quite a while until late this past summer, it started up again. Not sure if it was the same group, there were a lot more of them this time, and they were far more belligerent than before. One of the older boys even had the balls to question what I was doing at their party site. I really felt like smashing him in the face with the butt of my AR, but kept my composure at least in my actions. After this we sent trespass notices to all of the families in the nearby neighborhood, along with pictures of beer/alcohol bottles and used condoms, hoping that this would wake them up. Obviously their parents did not care what their kids were doing as they still continued to use my land for their parties. So enough was enough. On one of their heavy party nights my fiance and I went out there again, I had my AR15 in hand this time, my gf had the PS90. We crept up on them, and ordered them to get on the ground face-down. I lit them up with my 1200 lumen Surefire M6 floodlight modded w/ three P7s from one side of the trail going in to the area they were at, my gf had the 650+ lumen Milky Roomsweeper from the othe side. Cut off any easy escape routes. I was screaming at them as loud as I could, but did not specifically threaten to harm them and we did not point our firearms at them. Called the county deputies out, they all got hauled away, and this time I pressed charges. Most of them are also being charged for underage drinking, a few are being charged with contributing to the delinquency of minors, and two boys who are 18 are being charged with statutory rape of a minor.
Nitroz, I don't know the laws where you are at, but here in IN, we were within the law in what we did in our situation. Here we can use any reasonable force necessary to remove trespassers from our property. I can be armed anywhere on my own property for any reason whatsoever. Many of the local law enforcement use the range on my property and we have had many conversations about this situation. We used less force than what the deputies here recommended. The last thing I would have wanted to happen was for this to escalate to a deadly force situation, esp considering that most of these were ignorant teenagers. But it would have been foolish to approach them unarmed. Who knows what any of these kids these days could be carrying and what they would do. With all of the prior reports that we had filed, the law is on our side with this one.
In your case, if you confronted the trespassers before calling the police, they probably knew you would do so which gave them ample time to get away. Next time, covertly make sure they are there, and then call the cops out right away. Might have a better chance at getting them next time. If for some reason you do want to handle ejecting them yourself, I would definitely recommend that you ask your local law enforcement what your rights are in your jurisdiction.