Pittsburgh police say a man upset that his ex-girlfriend wouldn't name their newborn son after him fatally stabbed her 15 times and beat her grandmother to death. Cesar Mazza, 25, is awaiting arraignment today on charges of criminal homicide and kidnapping. Police say he took his 3-month-old son from foster care and dropped the baby off at his mother's house May 6. Cops say the baby had blood on him and Mazza claimed his ex, Tionna Banks, 19, had tried to stab him. In reality, police say, they later found Mazza had stabbed Banks and killed Valorie Crumpton, 72. Their bodies were found May 7. (More Pittsburgh stories.)