A 34-year-old man landed a 20-year sentence for fatally shaking his infant son in the family’s central Minnesota home.

Robert J. Kaiser, of Farming Township, was sentenced in Stearns County District Court last week after a jury convicted him of second-degree murder.

With credit for time in jail since his arrest in 2014, Kaiser will serve slightly less than 11 years in prison and then the balance of his sentence on supervised release.

While the boy’s mother was away for the day, Kaiser was caring for 2-month-old William John Polries-Kaiser in late August 2014 and became angered that the child was not allowing him to sleep. Kaiser shook the boy, inflicting brain injuries. He died a week later in a St. Paul hospital.

The mother, Ginger Polries, told authorities that a text from Kaiser earlier that day said the boy was keeping him awake.

Kaiser told investigators that William fell and hurt his head.

Along with detecting brain trauma, the autopsy revealed that the baby had broken ribs and other injuries in various stages of healing that were likely indicators of abuse.