The older brother of an 8-year-old Palmdale, California, boy who was allegedly tortured and killed by his mother and her boyfriend in May 2013 recounted a harrowing tale of abuse Wednesday, telling a jury his sibling was forced to eat cat litter and cat feces and was repeatedly beaten in the months leading up to his death.

Gabriel Fernandez's 16-year-old brother, who was identified in court only as Ezequiel C., told jurors he recalled his little brother being hit by his mother, Pearl Sinthia Fernandez, and her boyfriend, Isauro Aguirre, and frequently being kept in a "box" in the couple's bedroom.

"I noticed two beds in your room, but Gabriel still stayed in that box most of the time?" Deputy District Attorney Jonathan Hatami asked the teenager in reference to photos showing the bedroom the brothers shared.

"Yes," he responded.

His testimony -- along with the testimony of the boy's older sister -- came on the third day of trial for Aguirre, a 37-year-old former security guard who is charged with murder in Gabriel's May 22, 2013, fatal beating. He also faces a special circumstance allegation of murder involving the infliction of torture.

Prosecutors are seeking the death penalty against Aguirre and Fernandez, 34, who will be tried separately.

The boy's death triggered investigations into the county's child welfare system and resulted in the filing of criminal charges of child abuse and falsifying public records against two former county social workers and two of their supervisors, who are due back in court Friday for a pretrial hearing.

During his opening statement Monday, Hatami told jurors the youngster was systematically tortured because Aguirre believed the child was gay.

One of Aguirre's attorneys, John Alan, acknowledged that Aguirre committed "unspeakable acts of abuse" against Gabriel before "exploding into a rage of anger" that resulted in the boy's death. But he told jurors the evidence would show that "Isauro never intended for Gabriel to die."

On the stand Wednesday, Ezequiel said it was tough to remember what had happened to his younger brother and that it makes him sad. Be he acknowledged that he recalled the details after repeatedly being asked in court to review a copy of a transcript of his testimony before the grand jury that indicted his mother and Aguirre.

The boy's older brother said he recalled Aguirre often calling his youngest brother gay, and some times placing a sock in -- and a bandana over -- the boy's mouth.

"So, Gabriel was in the box for months and tied up like he was?" the prosecutor asked.

"Yes," the teen responded.

He said Gabriel was hidden in the box when social workers came to their apartment and that his mother and her boyfriend told him to lie about his brother's injuries and to say that they occurred while the two boys were playing.

Aguirre would sometimes put make-up on the boy to cover his bruises, the teen said.

The teenager said he also recalled his younger brother being kicked and being struck by Aguirre with the metal part of a belt, a metal hanger, a wooden club and a baseball bat, along with being shot with a BB gun in the face and groin area.

"Is it tough to remember that?" the prosecutor asked.

"Yes," the boy responded.

He testified that his mother also kicked Gabriel in the groin area, hit him with a broomstick, punched him and forced him to wear girl's clothing to school. He said his younger sibling -- who would take other clothing and change in the school restroom -- was hit once by his mom after she caught him.

The teen testified that he remembered his mother and Aguirre putting the boy in the bathtub and Aguirre spraying him in the face with pepper spray.

He said his mother and her boyfriend also made the boy eat "spoiled or expired stuff," telling jurors he remembered the boy being forced to eat old spinach, and when Gabriel vomited, he was told to eat the vomit off the table.

"They'd make him eat the cat litter and the cat poop," he also told jurors.

The teen said his mother hit him after catching him trying to sneak food to his younger brother.

He said his mother told him to tell police or paramedics the night of the 911 call that the boys were playing when the 8-year-old hit his head on a cabinet.

On cross-examination, defense attorney Michael Sklar asked the teenager, "Why do you think Gabriel was hurt so much and not you and (your sister) Virginia?"

"I don't know," the teen responded.

The boy's teenage sister, identified in court as Virginia C., broke down in tears when she was shown a photo of the boy. The judge instructed jurors to take a five-minute break, and the teenage girl confirmed when court resumed that it was a photo of her younger brother.

She testified that she saw Aguirre repeatedly punching the boy, and that her mother knocked his two front teeth out. "Did he cry?" the prosecutor asked. "Yes," she said, wiping her nose and one of her eyes.

She responded affirmatively when asked if the beatings happened a lot, wiping one of her eyes after testifying that Aguirre had shot her younger brother with a BB gun.

When asked whether Aguirre put her youngest brother in a cabinet -- which was across the room from her in court and which was referred to earlier in the day by her older brother as a box -- she said, "Yes ... a lot."

The boy slept in the cabinet, which had handcuffs attached so he couldn't get out, she testified.

The teenage girl appeared emotional throughout her testimony, wiping one of her eyes after testifying that Aguirre had shot her younger brother with a BB gun.

"Did Gabriel ever have to wear any type of girls' clothing?" Hatami asked. "Yes," she responded, noting that her mother and Aguirre had both called the boy gay.

The teenage girl -- who is set to continue her testimony Friday after a one-day break in the trial -- told jurors she was sitting on the edge of a bed and "my mother's boyfriend was punching him" the night her youngest brother was fatally beaten.

"He had knocked the air out of him and he fell over and he didn't get back up," she said through tears. "So they picked him up, they threw him in the shower and they kept yelling at him to wake up. When he didn't wake up, my mother decided to call the police."

Paramedics and Los Angeles County sheriff's deputies responded to the apartment after the couple called 911 to report that the child was not breathing.

The youngster -- who had missed school for two weeks -- was declared brain dead that day and was taken off life support two days later.

In testimony Tuesday, two registered nurses who work in the pediatric intensive care unit at Children's Hospital Los Angeles told jurors that the boy was covered in injuries.

"It seemed like every inch of Gabriel was bruised and swollen," one of the nurses, Emily Rebar, said.

She said he had so many injuries it was hard to keep track of all of them.

Another nurse, Jodi Mercier, testified that the youth "looked like a shell of a boy," noting that he had "multiple injuries all over his body."

A Los Angeles County sheriff's deputy who responded to the home the night of the 911 call testified that the boy was "heavily bruised all over his body and face" and that he spoke with the boy's mother and her boyfriend.

When Aguirre was questioned about the boy's extensive bruises, he responded that the boy was very angry and would hurt himself a lot, and had also been injured in a bicycle accident a few days earlier, according to sheriff's Deputy Ronald McCarthy.

The boy's mother -- who had a "disinterested" demeanor when she was being questioned about what had happened to the boy -- expressed concern about the family's seven cats being left alone in the apartment in a cage, the deputy testified.