Authorities began investigating Wednesday, when the infants' mother brought them to Hackensack University Medical Center because one of the children did not appear to be responsive. The babies had both suffered fractures and head trauma. The other child was in stable condition, authorities said.
Teaneck police and the prosecutor's office determined the children had been in the care of their father, Jonathan Melendez, 27, when the children were injured.
Melendez was arrested at the hospital Friday and charged with two counts of aggravated assault and two counts of endangering the welfare of a child. He was being held at the Bergen County jail pending an initial appearance in processing court Saturday.
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