A father in Minnesota is facing second-degree murder charges for the death of his 4-month-old son, who died in late April.

According to a criminal complaint obtained by the Twin Cities Pioneer Press, Matthew Hoisser, 35, told investigators that he dropped his son, Gus Hoisser, on his head because he “was crying and fussy and was being ‘difficult.” Hosier was left in charge of the baby on the evening of April 24 but had difficulty getting him to sleep.

“At one point, (Matthew Hoisser) was so frustrated he intentionally dropped the infant head first into the ground … intentionally causing him to fall to the ground and strike his head on the floor stunning (the baby) and causing him to continue to cry,” the complaint alleged.

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The boy’s mother, Nicole Hoisser, reportedly claimed that she tried to feed her son at 6:30 a.m. the next morning but he was “whimpering” and barely drank his bottle. She took her son to a childcare provider, who put him down for a nap at roughly 10 a.m, court documents stated.

The childcare provider reportedly described Gus Hoisser as “awake and fussy” when she checked on him. She said she changed his diaper and found him “limp and quiet,” according to the Pioneer Press.

The provider called 911 and performed mouth-to-mouth resuscitation before emergency crews arrived. Gus Hoisser was taken off of life support five days later, according to WCCO.

The baby’s cause of death was listed as blunt force trauma—with doctors saying his head injury was so serious it would’ve left him permanently blind, deaf, and immobile.

The Pioneer Press reported that there were also signs of hemorrhaging along the infant’s spinal cord.

The infant’s father allegedly also admitted that his son’s head hit the uncarpeted floor a few weeks before the deadly incident. He told investigators that he wasn’t always “super gentle” with his son, as there were instances where he would become short with him, WCCO reported.

Matthew Hoisser was charged with murder on Friday, three months after his son’s death. According to reports, Nicole Hoisser is currently 10 weeks pregnant with his child.

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[Featured image: Gus Hoisser/GoFundMe]