Investigators have recovered a body believed to be that of a 20-year-old Iowa college student who vanished from a small town one month ago.  Greg Willey of Crime Stoppers of Central Iowa said he learned of the discovery from a close family friend of Mollie Tibbetts on Tuesday morning. Willey says he has no other details about the discovery, but called it a “tough” ending to the search for the University of Iowa student.  The Iowa Division of Criminal Investigation plans a news conference for 5 this afternoon to update the public on the case. A spokesman for the agency has not returned a message seeking comment.  Tibbetts vanished on July 18 from her hometown of Brooklyn. Investigators said she was last seen on a routine jog through the streets of the city. It’s unclear whether she returned to the home where she was dog-sitting for her boyfriend and her boyfriend’s brother, who have said they were both out of town.  A reward fund has raised nearly $400,000 for any tips that led to Tibbetts’ safe return. Willey says the fund will now likely be used for any information that helps police catch any person responsible for her death.