Pittsburgh-area man charged with killing girlfriend's 1-year-old boy

NEW CASTLE, Pa. (KDKA) -- A New Castle man is charged with homicide in the death of his girlfriend's 1-year-old child.

Twenty-one-year-old Isaias Robles Nieves was charged Tuesday with homicide, aggravated assault and endangering the welfare of children in the death of Noah Santiago in January of 2023.

The boy was found unresponsive after first responders were called to a home on Altman Road in New Castle on Jan. 19 for reports of a child choking. He was taken to the hospital, where he later died.

Months later, the Allegheny County Medical Examiner's Office said Santiago died from blunt force trauma of the head and trunk, ruling his death a homicide. 

According to the criminal complaint, there was a hole in the closet door by the crib. Police took DNA swabs from that hole and found DNA from the boy and his mother.

An officer asked the doctor, "If an adult held a child and slammed that child into the wall striking the child's head, would this be enough force to cause the damage that was located during the autopsy?" The doctor answered that it was certainly a possibility, police said. 

Before his death, investigators said Santiago was treated for a leg fracture, and when he came back for another visit, he had two leg fractures. The story was that the boy's leg had gotten caught in the slats of his crib, but a doctor told investigators that didn't add up.

After Robles Nieves was arrested, KDKA-TV asked about the hole in the closet. "I punched it because I couldn't get in the ambulance with my stepson," he said. He also denied any alleged prior abuse.

The boy's mother told police that she had never seen her boyfriend be abusive to any of her children. According to the criminal complaint, the boy's mom was working and said Robles Nieves was watching the boy and his 10-year-old brother. Police said they have a video that shows Noah was fine 30 minutes before 911 was called. 

Robles Nieves has been denied bail.