The victim, Howard Dunkin, 58, of the 200 block of South Burhans Boulevard, was in fair condition Sunday night at Washington County Hospital.
According to Renner, Dunkin awoke at about 1 a.m. Saturday morning to find a man punching him in the face while he rested on his couch.
"When he woke up, there was a male on top of him, straddling him, beating him in the face with his fists. He just jumped on top of him and just started beating him That's about all the victim remembers," Renner said.
Renner said the man also grabbed cash from Dunkin's pockets and ran out the door.
Dunkin remained in his home for about 16 hours, until he was discovered by family members who called police. Officer Todd Webster arrived at about 9 p.m. and immediately drove him to the hospital, Renner said.
"His eyes were swollen. His nose was swollen. He had dried blood on his face. He's really beaten severely," Renner said.
A bloody shirt left at Dunkin's house led police to Preston, Renner said. He said investigators traced the shirt to a man who told authorities that he loaned it to Preston Friday night. When they arrested Preston Sunday afternoon, they found other articles of bloody clothing, he said.
Renner said Preston told authorities that he had already spent the money taken in the robbery.
Even though Dunkin told investigators that he did not recognize his attacker, Renner said he believes they were acquainted. He said Preston told police that he had borrowed money from Dunkin in the past.