A northern Minnesota man suspected of long-running child abuse has been sentenced to 30 years in prison for fatally hitting his 23-month-old son.

Gary W. Jackson Jr., 26, of Redby, was sentenced in federal court in Bemidji on Thursday after pleading guilty to second-degree murder in connection with the death of Darren Earl Lee Jackson.

Jackson was in the midst of "a fit of rage" when he repeatedly punched his son at the family's home, according to the U.S. Attorney's Office.

After the attack, Jackson failed to seek the proper medical attention for the boy, and he died from blows to his head and torso.

After serving his 30-year prison term, Jackson will be on supervised release for five years.

Darren "enjoyed playing and chasing his cat, playing house with his sister, playing basketball, watching football and 'The Lazy Song' by Bruno Mars," the boy's online obituary read.

According to the criminal complaint:

Jackson left the home and asked a relative to look after the boy and two brothers. The relative checked on the boy, who "didn't look right," and called 911.

About 30 minutes later, Jackson started texting the relative and said, "I will never forgive myself, and I don't want to go to prison, I just wanna die too."

Police picked up the other children and saw bruises and other marks on them.

The boy's mother told authorities that she learned from a friend of Jackson's that he admitted to punching the boy because "he wouldn't stop crying."

She also said Jackson inflicted a skull fracture and broken arm on the boy in the summer of 2016.