Officials said blood and shell casings were found outside an east Madison restaurant Sunday after police received a report of shots fired.
The Madison Police Department said officers responded to a report of gunfire heard outside the Denny's on Thierer Road at 3:49 a.m.
Witnesses told police a fight in the parking lot was followed by shots fired.
Police said blood and shell casings were found at the scene but police had not located any victims Sunday morning.
Officers stopped two vehicles that left the scene and spoke to the occupants, the report noted.
Police said Jamal Greer, 20, was arrested after giving officers a false name. He was charged with obstructing and taken to Dane County Jail on a probation hold.