The Sonoma County coroner's office identified him as 21-year-old Enrique Alvarez Ramirez of Windsor. Results of an autopsy today are pending toxicology tests, the coroner's office said.
Ramirez was pronounced dead at the scene north of the Mendocino Avenue overpass at 1:57 a.m., the coroner's office said.
Sloat said what appeared to be a gunshot wound in the victim's right rear thigh was a compound fracture, and the CHP will now investigate the death as a hit-and-run.
The CHP will interview the family and friends of Ramirez to determine what he was doing before the incident, Sloat said.
A motorist stopped behind the victim's body, which was in the center of the highway. The CHP responded to the incident around 1:40 a.m., Sloat said.
The CHP briefly turned the investigation over to Santa Rosa police when it initially appeared the man had been assaulted.
Some lanes of the highway were closed during the investigation until 8:45 a.m.