Didn't really see a problem with Spelzer being released; Deb couldn't identify him, it wasn't his house and he could appear to be unconscious while being read his rights. Which only leaves that he was seen talking to the victim in a bar, not that much. Now the police probably would have put him under surveillance preventing Dexter from doing his thing, but the show stopped putting those kind of obstacles in Dexter's way a while ago.
