Has there been discussion that he picked not one flower, but two? That they are of different races? That, I believe, suggests some planning, that Mr. Ratliff was looking beyond just mere rape, towards a more involved scenario.
That he hunted out the place for the type of girls he needed to feed his fantasy. He did kill the boyfriends he took the time to tape them up. He didn't stop at one girl, he picked up a second ... that all goes to some level of strategy and planning.
Being there at that hour, in that particular place for the extremely likely purpose of engaging in illicit sex, the girls were already at risk, whether the direct fault of the parents is unknown, yet some parents actaully would permit and even encourage their daughters to follow their "spirits" in this matter -- and that is reckless parenting.
That such a vile predator as Ratliff would happen to show up, take them, rape them and nearly kill them is seems new twist, but it is really not the first time such things have happened in such places. Many rapes in such places, I suspect, go unreported.