A California father was arrested Sunday in the fatal shooting of his four children—all 12 years old and younger—and his mother-in-law.

The shooting occurred Sunday at about 10:30 a.m. inside their Lancaster home, Fox 11 reported. 

Germarcus David, 29, was arrested Monday on suspicion of murder, the report said. He turned himself in to the Lancaster Sheriff’s Station, moments before the children were discovered by their mother.

Grace Beltran, who lives three houses away, said a woman ran back and forth in their front yard, screaming, "My babies are gone! They’re all dead!"

A Los Angeles County Sheriff's Department statement says deputies found a woman, a girl and three boys with gunshot wounds

A Los Angeles County Sheriff's Department statement says deputies found a woman, a girl and three boys with gunshot wounds and paramedics pronounced them dead at the scene. (AP Photo/Ringo H.W. Chiu)

The Los Angeles Times reported that first responders arrived at the home and found the victims with gunshot wounds to their upper bodies. They were later pronounced dead at the scene.

Los Angeles County Coroner officials remove a body from a home where five bodies were found dead, in the city of Lancaster

Los Angeles County Coroner officials remove a body from a home where five bodies were found dead, in the city of Lancaster in the high desert Antelope Valley north of Los Angeles. (AP Photo/Ringo H.W. Chiu)

David was a licensed security guard and held a permit to carry a gun but it expired in August 2020 and was listed as canceled, according to records from the California Bureau of Security and Investigative Services, which regulates the private security industry.

California's city of Lancaster neighbors react to the deaths

Neighbors react near a home where five bodies were found dead. (AP Photo/Ringo H.W. Chiu)

What appeared to be David’s Facebook page includes a photograph of a crucifix and posts from late October and earlier this month offering spiritual and moral views.

"Just know that God loves you when you feel unloved for," David said in a Nov. 16 post.

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"The love I give will overflow from one heart to the next as a gift that keeps giving. I will be one of the reasons that others believe in the true goodness of this world," David posted on Oct. 27, adding: "THAT is what I want my legacy to be. THAT is what I want my children to grow up seeing."

The Associated Press contributed to this report