Deputies spotted the man who they said drove into a lot and fatally shot himself in the chest.
"The suspect, the husband, shot the person at the trucking company and then turned and shot his wife".
Two men were shot at a residence in Bakersfield, Southern California.
He then chased another man from the trucking company before he shot and killed him in front of a nearby sports store.
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.
The identities of the suspect and the victims were not released Wednesday night. The area of the shooting spree was in unincorporated Bakersfield, which is patrolled by the sheriff's department.
After carjacking a vehicle, the woman and child inside managed to escape.
The investigation could take days, he said, because there are at least 30 witnesses who need to be interviewed.
Deputies are now interviewing about 30 people who witnessed the string of shootings. The child and woman were not killed. Police are still investigating the motives behind the killings.
"Obviously, these are not random shootings", said Youngblood, while denouncing the fact that such mass shooting were "the new normal".
"I'm certainly speculating right now", Youngblood said.
Detectives are trying to determine the connections between all the victims and the shooter. "Our entire community, with one heavy heart, is praying for the victims and their families", he wrote.