When Julie is at the club andn Carla goes to dance with Tye she sees the killer holding on to the rail. You get three shots of him and each one gets a closer shot of him. On the third shot you can see him holding on to the railing. If you have seen I Know What You Did Last Summer you would know that he got one of his hands cut off and that the hook is now attached to his wrist

( as you can see). It's rwally not that hard to spot, and it's pretty cool to see.