A Montrose man who said he was frustrated with his infant daughter’s crying when he shook her and hit her head against a door frame pleaded guilty to second-degree murder Tuesday.

Darnell Jerome Davis, 27, was then sentenced in Hennepin County District Court for unintentionally killing Isabella, who was 5 months old.

He will spend 17 years in prison — two years more than Minnesota sentencing guidelines recommend, due to the age and vulnerability of the victim, as well as the “particular cruelty of the crime,” said Hennepin County Attorney Mike Freeman.

According to the criminal complaint, Davis was alone with Isabella on the morning of Aug. 21, 2016, before police were called about an infant who was not breathing.

At first, Davis told his girlfriend that their daughter had suffered a seizure. But he told first responders that he noticed the baby was not breathing normally after he gave her a bottle.

He said he panicked, shook her, and hit her head against a door frame while he “ran around the apartment,” the complaint states.

Later, Davis said that he was not sleeping well. He said the baby was crying after her mother left for work, and he picked her up and shook her.

She was rushed to Children’s Hospital in Minneapolis but died four days later.

In court Tuesday, Davis admitted that Isabella had been crying for 30 minutes and, sleep-deprived, he “panicked and shook his daughter harder than he meant to.”

Phillip Murphy, the baby’s grandfather, gave impact statements on behalf of the child’s mother and grandmother.

“You took her away from me,” the mother wrote. “She was the light of my life and now I have only darkness.”

On behalf of the baby’s grandmother, Murphy said, “You robbed my daughter of so many of Isabella’s firsts, her first tooth, her first steps, her first birthday. We will forever be heartbroken.”