The children’s mother made the grisly discovery in the city of Lancaster shortly after 10:30 p.m., with the kids’ father later turning himself in to police, Fox affiliate KTTV reported Monday.
Germarcus David, 29, is being held on $2 million bail after being hit with multiple homicide charges by the Los Angeles County Sheriff’s Department, the outlet reported.
Deputies answering a “rescue responding” call at the home found the grandmother suffering from gunshot wounds to her torso.
They then found the children — three boys and a girl — with similar wounds.
All five victims were pronounced dead, KTTV said.
David was questioned for several hours before he was charged, the sheriff’s office said.