I agree GeoriaPeach. I don't think there is any question Katie did NOT enter at Charles Allen, or she would have been caught on the camera. I suspect she and Bowie entered the park at the southwest corner, off of 10th, or on the west side at one of those two small streets between the buildings. Then she and Bowie walked east along the path or in the grass. I imagine Bowie would have preferred to walk in the soft grass at this point. They walked towards Charles Allen gate, either to exit there and go home, or turn around and go back to meet EC. I think the killer was just laying in wait there. Or perhaps the killer saw them enter the park and followed. However, I think the killer might have attacked them sooner and in a less travelled area then where he did.