A California man received a death sentence on Thursday for beating, starving, torturing and ultimately killing his girlfriend's 8-year-old son.

Isauro Aguirre, 37, was convicted of first-degree murder and sentenced to death. His girlfriend, 34-year-old Pearl Fernandez, was sentenced to life in prison without parole after pleading guilty in February.

Fernandez's son, Gabriel, was killed in a "beyond animalistic" way in 2013.

MOTHER PLEADS GUILTY IN SAVAGE DEATH OF TORTURED CALIFORNIA BOY, 8; EXPECTED TO GET LIFE IN PRISON

Prosecutors said he was repeatedly beaten, shot with a BB gun, forced to eat cat feces and slept while gagged and bound inside a small cabinet. According to Los Angeles County Superior Court Judge George Lomeli, the child once had his teeth knocked out with a bat.

Gabriel also suffered a fractured skull, broken ribs and burns across his body.

"It goes without saying that the conduct was horrendous and inhumane and nothing short of evil," Lomeli said in court on Thursday. "It's beyond animalistic because animals know how to take care of their young."

Pearl called 911 on May 22, 2013 to report Gabriel wasn't breathing. She told police her son had fallen and hit his head on a dresser.

The 8-year-old died two days later from blunt-force trauma and neglect.

His siblings testified that his mother and Aguirre would call him gay, punish him if he played with dolls and forced him to wear girls' clothes to school.

Pearl apologized during the court hearing and said she wished her son was still alive. She added that family members who have expressed grief over Gabriel's death are just looking for attention.

Several agencies investigated abuse allegations leading up to Gabriel's death. On several occasions, investigators concluded there was no evidence of abuse.

Prosecutors have since filed charges of child abuse and falsifying records against county social workers Stephanie Rodriguez and Patricia Clement and supervisors Kevin Bom and Gregory Merrittfour in Gabriel's death.

Fox News' Frank Miles and The Associated Press contributed to this report.