It says in her crotch, not in her, ahem, innermost secrets.
My reading is that the cops were in no way going to put there hands down a woman's pants, so they hauled her to the closest lady cop to do the honors.
But it also states that her pants sagged past her bum because of the weight of the stolen items, and the police report mentions that the aforementioned bum was completly bared through the window, which makes me think she was going commando...which means that there would be nothing to hold the Nesquik up but her...ah, thingy.