I also did a drive-by (DFU posted the pics I took), and yes, the parking lot is behind the fence line. The parking lot is not closed off by the fence, mind you. But if you are in the parking lot of this place, you're on their property, and I can think of no good reason for being there unless you're visiting the Islamic Center.
That was exactly my point. You don't go there unless you have business there. You don't take a short cut across the parking lot, because there is no such short cut.