Days after the murders, a neighbor remains in disbelief over what happened. The neighbor, who did not want to be identified, says his security cameras captured the nightmare.
He said the tragedy began soon after the children's father, 29-year-old Germarcus Lamar David, arrived at the home Sunday night.
"Within about two minutes of him being in the house you start to hear the gunshots," the neighbor recalled.
He said he heard screams coming from the home and two sets of gunshots.
Lancaster: Father accused of fatally shooting his 4 children, mother-in-law charged with murder
Lancaster: Father arrested in children's deaths charged with murder
Soon after David's wife came home, she was immediately overcome with grief and she began screaming, the neighbor said.
Only a few minutes passed before the mother went back outside.
"She's back outside on the phone with 911, screaming that her babies are gone," the neighbor said.
The neighbor says he turned the security footage over to detectives.
Los Angeles County Sheriff's Department detectives say the mother found the bodies of her children. She also found the body of her mother.
David turned himself in within minutes of his wife's arrival at the home.
The victims were identified by the L.A. County coroner's office as 51-year-old Erika England, 11-year-old Namyiah, 7-year-old Germarcus Jr., 2-year-old Kayden and 1-year-old Noah.
David was charged Tuesday with five counts of murder and three counts of assault on a child causing death. He made his first court appearance Wednesday, where his arraignment was continued.
He was ordered held in lieu of $10 million bail while awaiting arraignment Jan. 12.