After Elvis has disposed of Paul's body, he's driving Paul's car back to their father's house when he passes a clown walking away from a broken down car. Does anyone know what this is about? I remember a similar scene in Body Heat (in which William Hurt also appears) in which, while planning a murder, Hurt sees a clown driving a car.
(1) After the murder, I thought the film would play out like a conventional thriller. When I saw the clown, I thought, "Ah, after the police drag the river for Paul's body, that man-dressed-as-a-clown is going to be a witness who will place Elvis in the vicinity."
But of course, the film never did play out like a conventional thriller, which leads me to think that the director purposely placed the clown in the scene to lead us to that particular expectation (that the clown will later be a witness), only to then subvert our expectations completely. This makes the film more twisty and unpredictable for the viewer. In other words, the clown is a deliberate red herring.
(2) Elvis is mentally ill, probably a sociopath. In retrospect, maybe we're meant to wonder if this garishly dressed clown person was actually walking down the street or if he was just a figment of Elvis's troubled mind. Remember, Elvis had lugged Paul's body to his vehicle, drove to a remote location, disposed of the body, drove back, and then had to return on foot to his own rooming house. He was probably physically and mentally exhausted.