Brown said it was apparent the child suffered blunt force trauma. He said the child's body has been sent to Dallas for an autopsy.
"We will know a lot more after the autopsy results come back on what the weapon was, but we believe they may have used a hammer," he said.
Brown said the mother and stepfather both are 18 and their names have not been released yet since they have not been formally charged. They are set to be arraigned Wednesday morning on the charge of capital murder.
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