Noah Cuatro was in the custody of his parents, 27-year-old Jose Cuatro Jr. and 25-year-old Ursula Elaine Juarez, at the time of his death, despite efforts to remove him from their home. They reported his death as a pool drowning, but investigators deemed the incident suspicious.
The parents are facing one count each of murder and torture in the gruesome case. Cuatro Jr. also faces one count of assault on a child causing death and Juarez faces one count of child abuse resulting in death. If convicted as charged, both face a possible maximum sentence of 32 years to life in state prison.
Both suspects are expected to be arraigned Monday.
Prosecutors are recommending bail be set at $3 million.
The investigation began after authorities were notified that Noah had been transported to Palmdale Regional Medical Center, where he was pronounced dead. According to investigators, his parents said he was found motionless in a community pool in the 1200 block of East Avenue S in Palmdale on July 5.
"According to the hospital medical staff, they observed evidence of injuries to victim Noah Cuatro's body that was suspicious in nature and consistent with possible abuse," the Sheriff's Department said in a statement.
MORE: 'Justice for Noah' - activists call for DCFS accountability in Palmdale boy's death
On Sept. 24, the county coroner's office ruled Noah's death a homicide, officials said.
The boy had lived with his great-grandmother, Eva Hernandez, for a time under a court order. She said he begged her to let him stay with her and not return to his parents' home.
"I just wish they would have listened to him," Hernandez said in July. "He did say, 'Please don't do this, don't send me back.'"
On Sept. 26, Hernandez's attorney said the Los Angeles County District Attorney's Office had called her to inform her that the parents were arrested.
A report from the Office of Child Protection included social worker's concerns for Noah. An order that could've removed him from his home was issued in May but was never executed.
Hernandez's attorney, Brian Claypool, said they plan to hold the Department of Children and Family Services accountable.
"This little boy should've been removed from that house when he was two years old, let alone waiting until he was four and a half years old and watching him die," Claypool said.
The case remains under investigation by the Los Angeles County Sheriff's Department.
City News Service contributed to this story.