LE is adamant BG killed the girls and BG is a male. Everyone on the trail at that time is accounted for. Libby's female relatives are not on the trail.Why spend money testing further? Because most murder victims are killed by someone they know. I'm not saying THESE girls were, but it seems like police work 101 to me (my opinion)! Especially since the victims were children! Why wouldn't they is a more logical question to me.
As always, JMO.