Dane County sheriff's officials said Mount Horeb man has been arrested on a charge of attempted first-degree homicide after beating a man with a baseball bat.
Koalton Peterson, 18, was arrested after the early morning attack Tuesday, according to a Dane County Sheriff's Office news release.
Sheriff's officials said Mount Horeb police were called to Oak Valley Road in the Village of Mount Horeb on a report of battery at about 12:20 a.m. Tuesday.
Police found Ryan Smith, 20, of Fitchburg, lying in the roadway. He was transported by helicopter to the University of Wisconsin Hospital in Madison with serious injuries.
"What we know right now is that there was a dispute between two men shortly after midnight, and one of them ended up very seriously injured. He's in UW Hospital right now, and it is unclear whether he's going to recover from those injuries or not," said Elise Schaffer, Dane County Sheriff's Office spokeswoman.
Peterson was not at the scene when police arrived, but he was located later and arrested on suspicion of attempted first-degree intentional homicide, according to the Sheriff's Office.
Schaffer said authorities are investigating what caused the attack.
"One thing that our detectives have learned during interviews today is that it is most likely drug-related, but at this point we don't know to what extent that plays a role in the dispute," Schaffer said.
Investigators are asking anyone with information about the incident to come forward.