The child's father, Carlos Rivera, 30, said he knew of the mother's activities, the sources said. But rather than seeking help for the children, Rivera regularly left Nathalyz in the care of her older siblings, who were between 5 and 9, the sources said. He spent most of his days doing odd jobs at an Olney garage.
If Rivera made $20, he said he would buy a pizza for the older children and formula for Nathalyz - propping her bottle between two pillows, he said, since the disabled child could not lift her arms.
Details of the child's condition and her parents' alleged neglect were described to The Inquirer by three law enforcement and public health sources.
Ramirez told authorities that her daughter was born blind and with severe brain damage. One person familiar with the investigation said the mother sounded as if her daughter's fate was inevitable because of her disabilities.
Doctors are unsure exactly what disabilities the little girl had from birth.
When Rivera was not around, the sources said, he left Nathalyz's feeding to her siblings, who all lived in the filthy Sommers Street house.
Neither parent sought help from child welfare agencies and they had not taken Nathalyz to a doctor in more than a year, police said. Around midnight Sunday, Rivera realized Nathalyz was not breathing and, instead of dialing 911, called Ramirez at a boyfriend's house.
Nathalyz was already dead when Ramirez brought her to Einstein Medical Center two hours later wrapped in a filthy blanket, authorities say. The child's bones were visible through her skin. At the hospital, roaches scurried across her body. The little girl was to turn 4 next month but weighed just 11 pounds - the weight of an average 3-month-old baby.
On Tuesday, Rivera and Ramirez were separately arraigned and held without bail on charges of third-degree murder, involuntary manslaughter, conspiracy, and endangering the welfare of a child. Attorneys for the couple could not be reached.
Rivera and Ramirez's other children were in the custody of the city Department of Human Services (DHS) on Tuesday after being examined by doctors who treated them for lice and bug bites, authorities said.
Investigators were trying to determine the last time Nathalyz's 8- and 9-year-old siblings were enrolled in school, if ever, the sources said. They said the two older children had not been to school since at least October 2012.
The Philadelphia School District did not return a reporter's calls seeking information about the children's enrollment status.
Crime scene investigators wore hazmat suits when they searched the couple's home Tuesday night. The home was an "absolute disgrace - filth, trash, excrement on the floors," said Lt. Mark Deegan of Homicide's Special Investigations Unit, which is handling the case.
Concerned that stairs leading to the second floor were unsafe, the Fire Department removed air conditioners so police could photograph the rooms from ladders, Deegan said.
"Of all the scenes I have been to, it is rare to have a house so dangerous that we cannot go in and do our jobs," Deegan, a veteran of three decades as a police officer, said. "If it was that dangerous for us, then what must have it been like for the five children in there?"
Nathalyz slept in a back bedroom, investigators said. Her parents often carried her about in a car seat, neighbors said. They said the couple rarely let the older children out front, and often used a rear alley entrance.
This summer, Ramirez brought Nathalyz to a family party where relatives saw her trying to feed the little girl mashed potatoes, the sources said.
They said some family members knew of the deplorable conditions in the couple's home.
DHS received a complaint about the couple in 2008, before Nathalyz was born, police said Monday. The agency said confidentiality laws prohibit it from discussing the family.
A child abuse pediatrician involved with the case said on Monday that given Nathalyz's weight, it is likely she was starved for many months, if not longer.
A preliminary hearing has been set for Ramirez and Rivera for Sept. 25.
Contact Mike Newall at 215-854-2759 or email@example.com., or follow on Twitter @MikeNewall.