SIOUX FALLS, S.D. » A man convicted in the death of the 2-year-old son of Minnesota Vikings running back Adrian Peterson has been sentenced to life in prison in South Dakota.

The child, Tyrese Robert Ruffin, died in October 2013. An autopsy concluded he sustained four blows to the head that doctors said couldn’t have been accidental.

A jury in September convicted 29-year-old Joseph Patterson of second-degree murder, which carries a life sentence. He was sentenced today.

Tyrese was the son of Patterson’s girlfriend and Peterson, who has said he found out Tyrese was his son about two months earlier.

Peterson had been working with Tyrese’s mother to arrange meeting the boy when he was told Tyrese was hospitalized. Peterson said he raced to South Dakota and saw Tyrese a day before he died.