He would catch my attention because his jacket is not a quarter or half or fully buttoned up. He buttoned up one opening at the bottom and skipped some openings and buttoned another higher up... why? Put the jacket on in a hurry and knows he's soon going to take it off again anyway? It looks uncomfortable and, with the extra junk he appears to be toting inside the jacket, I would wonder what was going on with him.
I still believe he has a brown hoodie on under the jacket so the jacket, imo, was a hurried addition to his "costume" in order to approach with tools he needed hidden from the girls. That's why, imo, there's something white sticking out of the top of the jacket... too much of a hurry to put the jacket on and catch up to the girls. And, he might have reasoned, if anyone saw him they'd tell LE he was wearing a blue jacket... not a brown hoodie. He could have had the jacket hidden in the woods near the beginning of the bridge... all packed up and ready to go. People might see him begin crossing the bridge, but they'd only see his back and he'd be wearing a blue jacket so they probably wouldn't connect him with the man they'd seen earlier wearing a brown hoodie. (And, when he was wearing the brown hoodie, it seems likely that quite a few would have seen his face.) However, probably very few remember the face of the guy wearing the blue jacket.
This could even account for there being 2 sketches. All jmo.