Kareem Leiva and Heather Barron were both charged with the murder of Anthony Avalos. Barron was also charged with torture.
The 10-year-old was found unresponsive in a home on East Avenue K last month. He was taken to the hospital, where he later died the next day.
Barron claimed that the boy fell and injured his head, while detectives believe that she and Leiva tortured him to death.
MORE: Lancaster boy's death may have been motivated by homophobia, officials say
Since the boy's death and the arrests of Leiva and Barron, the Los Angeles County Department of Children and Family Services has removed eight children from the home and taken custody of them.
As the couple appeared in court, a small group of protesters gathered and demanded justice for Anthony in Palmdale. They also demanded transparency from the Department of Children and Family Services, standing and marching in front of the office in the area.
Since 2013, DCFS reported receiving at least a dozen referrals for possible physical, emotional and sexual abuse of the boy. No such reports had been made in the last two years. Authorities are reviewing the agency's response to those reports.
Authorities said Avalos' sexuality may have been a motivating factor in his death.
If convicted of the charges against her, Barron faces a possible maximum sentence of 22 years to life in state prison. Leiva faces 32 years to life if convicted.