SIOUX FALLS, S.D. — A man serving life in prison without parole for the death of the 2-year-old son of Minnesota Vikings running back Adrian Peterson is appealing his conviction to the South Dakota Supreme Court.

Joseph Patterson last fall was convicted of second-degree murder in the October 2013 death of Tyrese Robert Ruffin, the son of Patterson’s girlfriend and Peterson.

An autopsy concluded the boy suffered four blows to the head that doctors said couldn’t have been accidental. Patterson maintained his innocence throughout his trial, saying the boy choked.

Patterson’s lawyer, Ellery Grey, filed an appeal last month.