Jurors deliberated for about six hours before returning the verdict against Isauro Aguirre, also finding true a special allegation that the murder was committed with the infliction of torture.
The jury must next determine whether Aguirre should be sentenced to death for the May 2013 death of Gabriel Fernandez, who was found unconscious with a cracked skull, three broken ribs and BB pellets embedded in his lung and groin when paramedics reached him.
He was declared brain-dead and taken off life support two days later.
Prosecutors will begin presenting evidence in the penalty phase of the trial on Nov. 27.
His mother, Pearl Sinthia Fernandez, is facing a separate trial. She has pled not guilty to murder.
The prosecutor told jurors in closing arguments this week that the 6-foot-2, 270-pound Aguirre clearly enjoyed torturing the small boy and had systematically brutalized him in the months leading to his death, forcing him to eat cat litter and feces and making him sleep bound and gagged in a small cabinet overnight.
“This was intentional murder by torture,” Hatami told jurors.

Aguirre took steps to cover up evidence of the ongoing abuse at the home before calling 911 to report that Gabriel had stopped breathing, the prosecutor said.
Jurors  now had the chance to do right by Gabriel Hernandez,  after so many had failed him, Hatami said: “The social workers had a chance. The school officials had a chance. The deputies had a chance,” he said. “Now it’s up to you…. What are you going to do?”
The boy’s horrific death led to unprecedented criminal charges against L.A. County social workers who allowed Gabriel to remain at the home despite six investigations of the mother and numerous reports of the boy’s injuries. Sheriff’s deputies also visited the home multiple times in the months before the killing, and prosecutors said in court papers that some of the deputies were later disciplined in connection with Gabriel’s death.

Gabriel Hernandez was failed by his loved ones and the social services system simultaneously

Pearl Sinthia Fernandez, has pled not guilty to murder in a separate trial in the murder of her son. Prosecutors said Fernandez and her boyfriend, Isauro Aguirre, tortured Gabriel to death

Aguirre’s defense attorney asked the jury to set aside their “complete horror” at what was done to the boy and recognize that his client never intended to kill Gabriel. He argued that because Aguirre brutalized the boy during a fit of rage, he was guilty of second-degree, not first-degree, murder.
“He was completely out of control,” said Deputy Public Defender Michael Sklar.
The attorney said that it was the boy’s mother who was responsible for much of the abuse, including shooting him with a BB gun and hitting him with a belt, and that Aguirre had attempted to perform CPR to revive Gabriel before paramedics arrived.
Sklar said Aguirre was himself a victim of abuse at the hands of his own mother, who disciplined him with cords and by burning him with cigarettes. He played for jurors the man’s tearful interview with sheriff’s deputies.
Gabriel’s killing galvanized calls for reforms in the way the county oversees abused and neglected children.
The slippage in the Los Angeles County’s child welfare system, was so appalling that in March 2017, a Los Angeles court ruled that four social workers should stand trial on child abuse and other charges in the death of the  8-year-old Gabriel they were assigned to protect, allowing prosecutors to push ahead with a case that has sent a chill through the ranks of child protection workers nationwide.
LA County Superior Court Judge Mary Lou Villar said that “red flags were everywhere” during the months before Gabriel Fernandez died and that the social workers mishandled evidence of escalating abuse and failed to file timely reports on what was happening in the Fernandez home before Gabriel was killed by his mother and her boyfriend in May of 2013.
Describing the conduct of the workers as criminal negligence, the judge Villar said: “[Gabriel’s mom] was in the system — that was a red flag, he missed school…had injuries, and his teacher called,” Villar said. “All of this shows that the mother was uncooperative and the parties should have known at that time something was wrong.”

Social workers Patricia Clement, [far left], Stefanie Rodriguez, [third  left], supervisors Kevin Bom, [second right], and Gregory Merritt, [fourth right], appear for their arraignment in March, facing the charge of criminal negligence

A blue-ribbon commission set up by the county Board of Supervisors recommended “a fundamental transformation of the current child protection system.” The board responded by setting up a new agency, the Office of Child Protection, which is charged with improving how children are treated.
The Sheriff’s Department also had been changes as a result of the case and others like it. Reports taken by patrol deputies are more extensive now and that there is better handling and tracking of those reports; “The ultimate goal is that no child case should ever fall through any crack whatsoever,” Sheriff’s Det. Tim O’Quinn said.