A fourth suspect in an Oct. 6 shooting that left a Santa Rosa man dead in a Todd Road parking lot has been arrested, along with his girlfriend, a suspected accessory to the crime, the Sonoma County Sheriff's Office said.

Fernando Lopez-Castillo, 25, was apprehended Wednesday evening at the Phoenix Lodge Motel in Hayward, where he and his girlfriend, Anna Velasquez, had been staying for several days, authorities said.

Lopez-Castillo was arrested for suspicion of murder, robbery and conspiracy to commit a crime in the shooting death of Jose Manuel DeJesus, 33, authorities said.

Lopez-Castillo is being held at the Sonoma County Jail without bail, like his older brother, Juan Ramon Lopez-Castillo, 28, who also a suspect in the case, authorities said.

Two other men, Hayward resident Alberto Barraza Lopez, 33, and Jose Carraballo Mejias, 54, of Santa Rosa, are also being held in the case.

Investigators say DeJesus had gone to the rural Carnicer? Contreras on Todd Road in south Santa Rosa to meet buyers for a cache of marijuana he was selling when he was shot in the head and left dead in his car in the gravel parking lot on the afternoon of Oct. 6.

No marijuana was left in the car, sheriff's Lt. Dennis O'Leary later said.

Two of the suspects, the elder Lopez-Castillo and Barraza Lopez, were arrested Saturday afternoon outside a San Mateo County apartment complex, the sheriff's office said.

Mejias was apprehended Monday morning during a traffic stop on Farmers Lane and Highway 12 in Santa Rosa, authorities said.

Fernando Lopez-Castillo remained at large until Wednesday evening.

All four are being held without bail on the same charges.

Bail for Velasquez is $10,000, Sonoma County Jail personnel said.

There are no additional suspects outstanding, authorities said.