The tow truck driver was identified as Marvin Erickson, 67, who had been shot several times.
State Police said an Oregon Department of Transportation worker found a car stuck in a snowstorm, noted the license number and called a tow truck. They said the driver of the car, Brian Pennington, 44, of Lacey, Wash., then reportedly shot the tow truck driver.
Pennington then drove to the parking lot of a restaurant where state police and Klamath County sheriff's deputies were assembling after learning that Pennington was wanted for homicides in Olympia, Wash.
Pennington drove behind the restaurant and shot himself in the chest, authorities said.
Police in Olympia are calling the deaths of two men in a home there a double homicide.
"The nature of the injuries is not consistent with suicide," Olympia Police Cmdr. Tor Bjornstad said. There was no sign of forced entry or burglary at the home, and no weapon was found.
Police were called to the home around 4 p.m. Sunday after a relative of one of at least two men sharing the house found one victim in a back hallway.
The victims were not immediately identified.
Neighbors said a family had lived in the home until a few months ago when the couple separated and the wife moved out with the three children. The husband had since gotten a roommate.