Sheriff Donny Youngblood told reporters that the suspect first shot a man at the trucking company and then killed his wife.
A gunman killed five people, including his wife, before turning the gun on himself as a Kern County sheriff's deputy closed in Wednesday, authorities said.
When he arrived at the residence, the suspect fatally shot two more men, the sheriff said. Sheriff's deputies say a husband and wife went to a business, and the husband shot and killed his wife, as well as a man inside the business.
According to police, the shooter killed himself when confronted by a deputy.
"Obviously, these are not random shootings", the sheriff said. "It happened rather quickly of course", Youngblood said. The shooter commandeered a vehicle with a woman and a child inside.
Investigators are questioning around 30 witnesses in the case.
Bakersfield is a city of approximately 380,000 residents in southern California, about 100 miles north-northwest of Los Angeles.
The man then hijacked a auto with a woman and a child inside in Fillmore, which is about 100 miles from Bakersfield. Another man entered the business and tried to run. The identities of the attacker and the victims have not been made public yet.
It was also not known what had sparked the shootings, which saw all six people die in a short amount of time, Mr Youngblood said.
Authorities have not determined a motive in Wednesday's shooting spree in Bakersfield, however, they are confident a connection between the gunman and all five victims will be found.
Sheriff's officials said there were multiple crime scenes, including at the trucking business and near a gun seller called Bear Mountain Sports.