Placing someone under citizen's arrest for trespassing in Florida?

We moved into a new house in a small gated community in South Orlando in april 2010 and everything was going fine until maybe 2–3 days later I noticed some people jumping the fence and some even braking/popping the corner of the fence in order to cross our yard and go to their friend’s house. Our biggest problem is that most of them are minors 8yrs-16yrs but we have seen some people that look to be well into their 20s. We do have a security camera installed out back because the neighbors told us that this particular house has been broken into by people jumping from the other two communities that share the fence with us and the fence has “Private Property” signs on all 3 sides BUT what good is a camera if I don’t know the names of the people jumping, where they live and by the time they see us they either jump back or start running as we tell them to stop jumping & braking the fence. I have called the non emergency number but by the time they get here the kids are gone. What can I due? I was planning on planting some rose bushes along the fence but some one told me that if they get injured WE are responsible for it even if they are on our property.