Lawyers for Oscar Sanchez-Rivera, 24, and Viameri Santana-Berrios, 27, strenuously contested the charges during a five-hour preliminary hearing before Municipal Court Judge James M. DeLeon.
"There is nothing to indicate that my client ever injected this child with anything at any time," said F. Michael Medway, the attorney for Sanchez-Rivera.
Though Sanchez-Rivera is an admitted heroin user, Medway argued that it made no sense for him to inject and kill a child who was not his and whom he and his girlfriend were only watching. "Why? Because the kid is too much of a pain?" Medway asked.
Santana-Berrios' attorney, Rania M. Major-Trunfio, made a similar argument, telling the judge that neither the autopsy nor any witnesses could show that Santana-Berrios injected drugs into the infant she was watching for her cousin.
But Assistant District Attorney Bridget Kirn cited the testimony of Assistant Philadelphia Medical Examiner Edwin Lieberman, who said the drugs in Milton's body had to have been ingested or injected within six hours of death.
"For 391/2 hours, this baby was in the care of these two people," Kirn argued. "Take a look at the math and at the level of care and how they acted. The body has track marks. Track marks on a baby."
DeLeon agreed with Kirn: "It comes down to the six hours before the child died."
DeLeon ordered Sanchez-Rivera held on a general charge of murder, conspiracy, child endangerment, and related counts.
The judge held Santana-Berrios on third-degree murder and related charges. The lesser homicide charge made the mother of two - an 8-year-old boy and a 5-year-old girl - eligible for bail, and DeLeon set bail at $150,000.
Schroeder, the paramedic, testified that he and his partner responded to a 911 call at 2:36 a.m. on July 26, 2011, at an apartment in the 4500 block of North Seventh Street.
Schroeder said Santana-Berrios led him to a bedroom where he saw Sanchez-Rivera standing over the prone body of a baby who was naked and lying on a towel on the bed.
The child was cool to the touch, pale, and unresponsive, and Schroeder's efforts failed to revive the child in the ambulance. Schroeder said he and his partner took the child to St. Christopher's Hospital for Children, where he was pronounced dead shortly after 3 a.m. At the hospital, the paramedic added, Milton's internal body temperature was already too low to register on a rectal thermometer.
Lieberman testified that the autopsy showed eight needle marks on the feet and hands as well as heroin and cocaine still undigested in the child's stomach.
Questioning witnesses, the defense lawyers each suggested the other's client could have given the child the drugs. They also implicated the boy's mother, Iris Rojas, cousin of Santana-Berrios, whose house collapsed and who had left Milton in her cousin's care.
But the judge returned to who was caring for Milton: "You start with nothing's the matter with the kid and then the kid drops dead. And there's nothing, nothing you did to put the child in harm's way?"
Contact Joseph A. Slobodzian at 215-854-2985, firstname.lastname@example.org, or @joeslobo on Twitter.