A Southern California father who shot and killed his four children and mother-in-law was sentenced Wednesday to life in prison without the possibility of parole, a witness at the court told The Post.

Germarcus Lamar David, 32, was convicted on March 12 of five counts of murder and three counts of assault on a child causing death in the Nov. 28, 2021 incident, according to abc7.

Neighbors of the family home in Lancaster heard gunshots and screams on the night of the shooting, according to the local outlet.

“Within about two minutes of him being in the house you start to hear the gunshots,” one neighbor recalled, according to abc7.

The children’s mother ultimately discovered the bodies of her four children and mother upon returning home that evening. Neighbors saw her running outside screaming “My babies are gone! They’re all dead!”

The coroner’s office identified the victims as David’s four children: Namyiah David, 11; Germarcus David Jr., 7; Kaden David, 2; and 19-month-old Noah David, along with their grandmother Ericka England, a 51-year-old veteran corrections officer at the Lancaster prison.

David turned himself in to the Lancaster sheriff’s office shortly after his wife discovered the bodies of her loved ones.

“No family should endure this type of tragedy, especially when the alleged perpetrator was responsible for their protection,” LA County District Attorney George Gascon said in a statement when the charges against David were announced.

“Our office has reached out to the family to ensure they have all the services and support they need during this difficult time,” he said.

Germarcus David was a licensed security guard and had held a gun permit, which expired in August 2020.