On Dec. 20 Joshua Sullivan, 21, pleaded guilty to murder in the second degree for violently shaking his seven-day-old son in 2013. Sullivan pleaded guilty to assault of a child for the shaking crime in 2014. Subsequently, the baby passed away from injuries sustained in the shaking and the murder charge was filed.

“Protecting the vulnerable and holding accountable those who harm the vulnerable is one of our main missions,” said Prosecutor Mark Lindquist.

On May 23, 2013, Sullivan was awoken at approximately 3 a.m. by his crying infant son. Sullivan got out of bed to check on his son and became frustrated because the baby kept “fussing.” He shook his son as he carried him up and down the stairs, causing his son’s head to hit the wall.

In the morning, the baby’s mother and Sullivan noticed that both of the baby’s eyes were swollen. They took him to the hospital. The baby had bruises on his face, arms, back and ear. He was also bleeding from his umbilical cord. Medical staff determined that the baby suffered non-accidental head trauma, resulting in severe internal bleeding. He underwent emergency brain surgery.

The victim’s 3-year-old sibling said Sullivan got “a mean look” and that “daddy squeezed the baby.”

Sullivan is currently serving a 16 year sentence for the assault charge. That sentence is expected to be set aside and Sullivan will be re-sentenced on the murder charge March 3, 2017.