Your close Stephanie, it's called a necropsy and you don't want to freeze the body because it ruins any tissue samples that the vet may want to send out. Most reptiles have the blue spot on their abdomens when they die. I think it has to do with the gall bladder but I'm not a hundred percent sure. I agree though the only way to know for sure is to have a necropsy done. I am very sorry for you loss.