A Hyde Park man was held on high bail yesterday for allegedly beating his infant son, fracturing two bones in his leg and seven of his ribs over the course of at least three months, Suffolk County District Attorney Daniel F. Conley said today.

CHRISTOPHER DUNCAN (D.O.B. 4/18/82) of Hyde Park was held on $25,000 cash bail during his arraignment in West Roxbury District Court on charges of assault and battery on a child, assault and battery on a child causing serious injury, and mayhem.

“If you have a crying baby and you find yourself losing patience, please take a few minutes to cool down,” Conley said. “The free Massachusetts Parental Stress Line is open 24 hours a day, seven days a week, at 1-800-632-8188. Asking for help doesn’t mean you’re a bad parent – it only means you care.”

Assistant District Attorney Ellen Bisson of Conley’s Child Protection Unit told Judge Michael J. Coyne that Duncan went with the mother of his two children to the Boston Medical Center on July 8 because his son, then 3 months old, would not stop crying.

X-rays taken of the child showed that his right tibia, his left femur, and seven of his ribs from both sides were healing from previous fractures. When asked what had happened, Duncan allegedly made statements indicating that the baby had rolled off of a bed. Doctors indicated that the child’s injuries could not have come from such an incident.

Later, outside the presence of doctors, Duncan allegedly made additional statements that the baby had been crying, that he grew frustrated, and that he snapped the baby’s legs. Because the fractures were healing, investigators believe that they had been sustained earlier and had been exacerbated by more recent physical abuse.

Doctors’ observations prompted them to notify the Department of Children and Families under a mandatory reporting program that also alerts the chief of Conley’s Child Protection Unit. Prosecutors in turn notified Boston Police detectives who, in the course of the ongoing investigation, obtained a warrant for Duncan’s arrest on Monday.

Duncan’s other child, a 17-month-old girl, is in the custody of her mother and grandmother. Neither of those adults is believed to have taken part in any of the abuse.

Conley’s office routinely consults with the Child Protection Team of Massachusetts General Hospital and other area hospitals in cases of alleged child abuse.

New parents can find additional support at www.OneToughJob.org, an online resource provided by the Massachusetts Children’s Trust Fund. Anyone who suspects a case of child abuse can call the DCF Child at Risk Hotline at 1-800-792-5200.

Duncan is represented by attorney William Concannon. He will return to court on Aug. 31.