The action — if action isn’t too strong in the context of Gus Van Sant’s latest downbeat meditation — partly unfolds at a skate park in Portland, Oregon. In the dreamiest scenes, skaters simply ollie and slide in slow motion, exotic fish in a concrete aquarium. Meanwhile, the film’s night-terror side develops slowly, as if Alex, the adolescent nonhero at the center, is too shy or scared to stammer out the truth. He killed a guy, accidentally, swinging at a rail-yard security guard with his board and knocking him in front of a train. Glum yet gorgeous, Paranoid Park ties together Alex’s bleak confusion with his more mundane existential teen traumas: his distance from a girlfriend he doesn’t like and from parents whom the camera never quite gets a good look at.