"Sadly, there is only one reason for it: his parents," Williams said. "Instead of caring and nurturing him, they ultimately caused his death by praying over his body rather than taking him to the doctor."
Brandon Scott Schaible was 7 months and 18 days old when he died April 18 of bacterial pneumonia, severe dehydration, and strep after his parents withheld medical care for four days.
The infant first developed a rash on his head, then became irritable with diarrhea and had little appetite, according to prosecutors and police.
Two days before his death, his breathing became so labored that he was breathing out of his mouth, Catherine Schaible told police.
But rather than call a doctor - as they were ordered to do under the terms of probation in the 2009 death of 2-year-old son Kent - the Schaibles called an assistant pastor to come and anoint Brandon and pray.
When the child stopped breathing, the couple told police, they prayed for him to be revived. Then they called a funeral home.
Members of a Juniata Park church that shuns medical care, the Schaibles were convicted of involuntary manslaughter after Kent died of bacterial pneumonia after a week-and-a-half-long illness.
In statements to police after Brandon's death, the Schaibles said, just as they did when Kent died, that they did not seek medical help because of their faith in God's power to heal.
First Assistant District Attorney Edward McCann said Wednesday that authorities "carefully considered" whether third-degree murder - which carries a maximum sentence of 20 to 40 years - was the appropriate charge in Brandon's death.
"How many kids have to die before it becomes an extreme indifference to the value of human life?" McCann said, noting the legal threshold of murder.
"When you are praying over your child when your child is not breathing, when you have a prior child who died of a clearly preventable disease, and when you were required by the court to seek medical treatment if your child was sick and you don't do so - based on all those circumstances, it was our assessment that the murder charges were appropriate."
The Schaibles face an additional seven to 14 years in prison, McCann said, if a judge decides to revoke their probation in Kent's death.
Mythri Jayaraman, an attorney for Catherine Schaible, said her client was "certainly shook up."
"I think she's more reeling from losing Brandon than she is from this arrest itself," Jayaraman said.
"To suggest Catherine was indifferent to her children's lives and health couldn't be further from the truth," Jayaraman added. "This is a woman who is a completely devoted mother."
The Schaibles are members of First Century Gospel Church, a congregation of about 500 members that rejects medical care and almost all modern health and safety precautions, including dental work, toothpaste, eyeglasses, even seat belts. Trust in medicine and doctors is a sin, according to church doctrine.
During Kent's trial, Jayaraman and attorney Bobby Hoof, who represented Herbert Schaible, argued that the Schaibles did not know just how sick their child was before he died - and that it was uncertain that medical attention would have saved the child.
Both lawyers said Wednesday that it was too early to discuss potential defenses in Brandon's death.
Assistant District Attorney Joanne Pescatore, who prosecuted the Schaibles in Kent's death and is handling Brandon's case, said Wednesday that the cases are "eerily similar."
"I knew something like this could have easily happened," she said of the second child to die. "I knew at their sentencing that they were not going to follow the judge's instructions."
The Schaibles' remaining seven children, who range in age from about 8 to 17, were immediately placed in temporary foster care after Brandon's death. They were allowed to see their parents during supervised visits and were permitted to attend a recent church service.
At the Schaibles' sentencing in 2011, a different judge ordered the probation department, rather than the city's child-welfare agency, to supervise the children's medical needs, a decision child advocates have criticized.
Brandon was seen by a doctor only once, just 10 days after he was born.
With the couple now arrested for a second time for following the church's most central tenet, the new charges seem to put First Century Gospel on the wrong side of the law.
"We're not in the business of prosecuting people for their sincerely held beliefs," McCann, the first assistant district attorney, said. "But if these beliefs again intersect with something like this - where it's clear that medical attention was needed by children - then on a case-by-case basis, we're going to have to deal with that."
McCann would not rule out whether the church pastor, Nelson Clark, could face charges as head of First Century Gospel.
"That is something we're going to have to consider looking into as we further investigate this case," McCann said. "It's not over at this point."
Clark told The Inquirer last month that the children died because of a "spiritual lack" on the part of their parents.
When asked Wednesday in an interview if he was concerned that he could be arrested, Clark said: "The thought crosses my mind, of course, because the buck stops somewhere. But I can't stop preaching what I think is the truth from the Bible."
District Attorney Williams said that the murder charges against the Schaibles should be a lesson to the First Century church members.
"We all believe in prayer," he said, "but as a complement and supplement to appropriate medical attention."
For his part, when asked what he would tell his church, Clark did not hesitate.
"We have to obey God rather than man," he said.
Church members met Wednesday night for a biweekly service. Parishioners filed in quickly to avoid the news cameras crowding the door of the hall on G Street.
Inside, families exchanged hugs as Clark played hymns on a keyboard. As the service began, Clark talked of eternal life, which he deemed an "appropriate" topic given outside events, and urged parishioners to remain steadfast while outside groups sought to "dissolve our faith."
Contact Mike Newall at 215-854-2759 or firstname.lastname@example.org or on Twitter @MikeNewall.
Inquirer staff writer Chris Palmer contributed to this article.