I don't know. The problem is that we don't know where either the killer or KJ were located at the time of the attack, but I would guess that it all started just out of camera view (or within view and we just don't know it) on the road near the bathroom, where Bowie ended up. Not knowing the extent of his injuries, we don't know if he was able to go any distance after he was attacked, but for now I'll assume probably not. While the killer was dispatching Bowie, KJ might have tried to fight him off the dog, or not, but either way she might have been able to run the distance to where she was found. She might have even sustained a stab wound before Bowie, but the killer then had to get the dog out of his way. These are details we just don't have.Perhaps that's right but of your description may be correct, how does Bowie end up near the restroom and Katie 100 ft further into the park? Why wasn't she murdered somewhere along the trail running path?
This all likely fits best with a random, opportunistic attack, imo. If she was stalked or it was someone who knew or followed her, the location of the attack might have been different. Idk. It's perplexing, really.