Yes, that could be an allusion to SD. But I also took it, in the context of the body language discussion, to hint around to something more about B, something like experience. I wouldn't go as far as contract killer, because wouldn't a professional be more clever than to have such a ridiculous staging? Also, I don't think serial killer necessarily either. But I get the sense that there is a feeling that he's at ease because he's done it before. If this is what they're thinking, maybe they're misreading his psychology, maybe he's so at ease because he's a narcissist? But I think AK must have some kind of evidence (of other crimes, murders?) to be going out on TV nearly everyday and dropping these kinds of hints. So the discussion of the body language is the way to hint around in the media, and clue in the public without saying anything about information LE has. JMO