Joseph Amoroso said before court that he came to support 2-year-old Bella Bond, the daughter he never met.
Michael McCarthy, 35, is charged with murder. Bella's mother, Rachelle Bond, 40, is charged as an accessory after the fact. They are to be arraigned in Dorchester District Court in Boston.
Amoroso said Bond told him that McCarthy punched Bella in the stomach over and over again until she stopped breathing.
