Just my speculation:
- This guy stalked the girls toward the southeast end of the bridge. He knew the trail ended there and that there would be significantly less chance of somebody happening upon them on that side of the creek. Maybe he passed them going the other direction and doubled back, maybe he saw them over that way from the NW side of the bridge and followed... not really sure. But I think he isolated them on that side of the creek.
- I think a trail cam or security camera mounted near the SE end of the bridge (most likely by one of the property owners near there) is what captured the picture or video of this . I also think he appears to have his left hand in his pants pocket, but his right hand in his hoodie pocket because he is holding a weapon that would not fit in his right pants pocket.
- Given that the property owner whose land the bodies were discovered on lived on the north side of the creek, if he stalked the girls to the SE end of the bridge, they somehow got back across to the north side. I can't imagine that this guy's plan involved entering the creek, so I can only figure that the girls crossed the creek trying to get away (it's shallow enough to walk across). This would also explain why there were quite a few LE folks searching IN the creek at that spot. You see LE vehicles parked as close as they can be to this location in the creek on both sides (cemetery to the north, gravel road near end of bridge to the south). I'm guessing this is where he caught up to them, probably just to the north side of the creek - it would be very difficult to climb the hill on the north side very quickly... it's very steep there as we saw in the video with the property owner.
That seems the most plausible scenario to me given what we know.
To speculate a little further, if he had a vehicle parked somewhere, he obviously would have taken the quickest route back to that location at that point. If he didn't have a vehicle, it seems unlikely that he would head west back toward the bridge or trail head... also seems unlikely that he would make the difficult hike up the hill to the north... also seems unlikely that he would go back across the creek toward the private residences to the south... so my guess would be, if he didn't have a vehicle, he probably followed along the creek bed or the banks to the east until he found a spot where he could get out of the area unseen.
Again, all just my speculation.