Hahah, you're a funny guy! Wait, there's nothing for Castro to prove. Oh, joke fail. Well, it's an ongoing investigation and he's a person of interest, so, yeah, there is. Wait a minute. There's nothing for him to prove. How is there nothing for him to prove? If there was nothing he had to explain then he could just ignore this and nothing would come of it and we wouldn't even be at this point. Until he explains his side of the story and the police decide whether or not there's something there he most certainly has something to "prove."