My guess it that she was abducted and severely abused by the transient she and her husband took in to their home the night before as part of some ill thought out and recklessly naive program organized by their church. She is probably still in some state of torture induced shock and didn't no where to go after her abductor released her. I sincerely hope that I am wrong but either way she needs out prayers.
In a way, you're very generous. I would like to think she didn't suffer this way. The cops apparently don't agree with your theory:
From the article:
Schaffer said investigators found the homeless man in Minnesota Wednesday and believe he has nothing to do with the case.
But we will have to wait and see what the truth is.