AK, at least, spent more than 40 hours at the police station over the next four days. When, exactly, did they go "on with their daily business as (though) nothing happened"?
What knife did RS clean and put back in his pocket? Is there now evidence that another of RS' knives was used in the murder?
How many hours did other suspects spend at the police station? All of Meredith's close friends were there as long as Knox on the first day ... was that 12-15 hours? I think we need to keep things in perspective, so mentioning that Knox was questioned for x number of hours means little on its own. What about Sofie? How many hours was she at the police station, waiting to be questioned ... sitting next to Knox? How many times was she asked to come in to clarify her answers? What about the guys in the downstairs cottage that were out of town at the time of the murder ... how many hours were they at the police station?
When did the pair have time to smooch in the lingerie department at the fashion shop?