A Rollingstone couple returned home Sunday afternoon to find their house sitter dead in the back yard, the Winona Daily News reports.

According to the paper, the 57-year-old man was found lying face-down in a pool of blood in the back yard. A trail of blood led police to a park almost two blocks away, where they found the victim's glasses and even more blood. He had been watching the house while the owners were out of town.

Winona County Sheriff Dave Brand told the paper that the cause and the time of death were not yet known, although the man did not appear to have been shot. His identity has not yet been released, pending notification of his family.