MINNEAPOLIS (WCCO) – A 26-year-old West St. Paul man is accused of assaulting his 4-month-old daughter last week, causing the infant head trauma, according to charges filed Monday in Dakota County Court.

Michael Joseph Mason was charged with one felony count of first-degree assault causing great bodily harm in connection with the Feb. 17 incident.

According to the charges, West St. Paul Police were called to a hospital after a 4-month-old baby had been suffering from head trauma. Mason reportedly brought the infant to the hospital after he tripped while carrying the baby, causing the infant to fall and possibly hit her head on a baby swing before hitting the floor.

Mason said he was taking care of the baby while her mother was at work. He said he was holding the baby girl on Feb. 17 when she fell asleep. He got up to put the baby in her crib, but fell over a chair on his way, according to the complaint. He said the baby fell from his arms and landed between a swing and a television.

The baby’s mother took her to the hospital the next day after she had thrown up food and was acting fussy, the complaint states. A medical examination showed the baby had bruising and three or four skull fractures and hemorrhages in both eyes. Authorities said the injuries were not consistent with an accidental fall.

Mason told police he starting shaking the baby before he tripped and fell, but thought he was being playful. The baby’s head struck the floor hard more than once while he was shaking her, according to the complaint. He said he started “freaking out” when the baby passed out and was not moving.

Mason also told police he got angry with the girl’s mother earlier in the day because she had misplaced his car keys, and he needed to move his car to avoid a $300 fine.

He said he was scared and nervous to tell the girl’s mother about her injuries, the complaint states.

If convicted, Mason faces up to 20 years in prison and a $30,000 fine.