How can i catch the kids smashing my mail box?

in the past three weeks my mail box has been smashed three times. My parents think its some kid in that knows me or my brother and we got on there bad side. I'm getting really sick of this and i want to catch the kids doing it. Is there a cheep camera i can hook to my fence that can see in the dark? is there some way to video tape them doing it? i want to be able to get a video if the people smashing my mail box and there license plate number. There is a fence right next to my mail box that i could put a camera on, and the camera should have a light cuz then they will know its there. thanks for your help:)