SIOUX FALLS, S.D. — A man accused of killing the 2-year-old son of Minnesota Vikings running back Adrian Peterson two years ago is set to stand trial in South Dakota.

Joseph Patterson pleaded not guilty to second-degree murder and other charges in the 2013 death of Tyrese Robert Ruffin, who was the son of his girlfriend and Peterson. Opening statements are scheduled to begin Tuesday in Canton, about 20 miles southeast of Sioux Falls.

Investigators allege that Patterson assaulted Tyrese on Oct. 9, 2013, while the two were alone in a Sioux Falls apartment. An autopsy concluded that the boy’s head sustained four blows, causing his brain to bleed, and doctors determined that the injuries could not have been accidental.