There was an anonymous police source on Sunday talking about a rifle in the trunk (not a shotgun). Aside from that, no other stories. Also the first video clearly shows a shotgun taken from the trunk.
Palmer, I wasn’t convinced it was a shotgun. I did think I saw a magazine on the weapon once it was turned away from the camera, and you could see it bottom to top on it’s side.
A person above made some comments about clearing the weapon that made pretty good sense. You may want to check that out since it concurs with your take on it.
http://www.freerepublic.com/focus/news/2969802/posts?page=45#45