The incident happened Sunday night on H Street in Mojave, according to the Kern County Sheriff's Office. Deputies responded to the area around 11:20 p.m. and found them suffering from gunshot wounds to the head, authorities confirmed to ABC News.
Three of the victims were pronounced dead at the scene. The fourth person was taken to the hospital and later died.
The relationship between the four victims is unknown.
Homicide detectives are now trying to determine what exactly led up to the deadly assault, but the limited eyewitnesses to the shooting made it "difficult," according to a representative from the sheriff's office.
A description of a possible suspect was not available.