That might be another reason for the "same type" sites...the camera setups are similar, can be located easily and can be avoided.
That's why I'm thinking the vehicle is in the next lot over, "spotting for the sniper" who is on foot for the actual shoot and they're using two-way radios. We have six units which we use at our cottage to keep in touch...it's 100 acres.
Sac
I don't know why they just don't put up a high altitude reconnaissance aircraft with high resolution, wide angle cameras and have it orbit the region for a few days, then when the next shooting occurs, lets look at the pictures...
It would not surprise me if this is being done now.