Jarrod Joseph Miller, 29, is accused of the first-degree murder of Timothy Neuer, 29, of Healdsburg on March 8.
He is being held under no bail in Sonoma County Jail and is scheduled to appear in court Wednesday when a preliminary hearing date will be set.
Neuer's girlfriend Amanda Miller called the sheriff's office around 11:20 p.m. on March 8 to report her brother shot her boyfriend and left the residence in the 300 block of Alexander Valley Road in unincorporated Sonoma County in a white Chevrolet Suburban.
She said her brother showed up at the house shortly before the shooting.
Windsor police arrested Miller during a traffic stop on Old Redwood Highway north of Limerick Lane in Windsor shortly after the shooting.
Miller said he threw the gun out the vehicle's window just before he was stopped by police, sheriff's Lt. Steve Brown said. A California Highway Patrol officer found the gun in a vineyard 500 yards north of where Miller was stopped.
Deputies found Neuer's body on the floor inside the residence. He was shot several times, Brown said.
Sheriff's Lt. Dennis O' Leary said all three once lived in the house but Miller had recently moved to Cloverdale.
Miller also is charged with use of a weapon causing great bodily injury. Deputy District Attorney Scott Jamar said the gun that killed Neuer was a .30-caliber semi-automatic pistol.
Miller faces 50 years to life in prison if he is convicted of first-degree murder and the weapon charge, Jamar said.