I think it's rather obvious that if Jennifer's body is intact, and if the girlfriend is honest in her deposition, Jennifer's body would have been retrieved yesterday. Instead, a significant piece of evidence was located and Jennifer is not found.
I suppose that means that the 30 pieces of evidence, 5 of which were found and had contained blood, may have been the disposal of her body. The husband, with his girlfriend, calculated how to leave her body in 30 different trash cans on garbage day. What was their next step - pick up the mail and pretend that everything was normal?
She knows perfectly well where the body is. Her phone was right next to his while they hid evidence in 30 trash cans along a garbage pickup route.