State Police said Clayton Mibroda beat his 20-day old daughter Natalee at a Bolivar home in December 2011. She later died at Indiana Regional Hospital.
Thursday he testified when he spoke to investigators, "I was protecting my children's mother."
Investigators testified Wednesday that Mibroda changed his story several times and told them his son was his "favorite" child. One trooper said that the father told them the little girl was always crying and he was frustrated he couldn't figure out what was wrong.
Mibroda told the jury he 'never thought in a million years his children's mother would hurt them - even though her depression concerned him."
WTAJ New's interviewed Mibroda's mother in 2012 who said she believed her son is not responsible for her granddaughter's death. Vickie Fetterman has custody of the couple's oldest son who will be 2 next month.
Closing argument begin Friday in Westmoreland County.