Prosecutors have filed criminal charges against four Los Angeles County social workers in connection with the death of a boy who authorities say suffered horrific abuse at home.

District Attorney Jackie Lacey says in a statement Thursday that the social workers are charged with child abuse and falsifying public records involving 8-year-old Gabriel Fernandez who died in May 2013. His injuries included a fractured skull, broken ribs and burns. Lacey says the four were negligent in Gabriel's death.

The Department of Children and Family Services had opened a case on the boy in October 2012.

The four social workers include two supervisors. If convicted, each faces up to 10 years in prison.

The boy's mother and her partner were arrested in Gabriel's death and prosecutors announced last summer they will seek the death penalty against the Palmdale couple.