Sergio Brown, a former NFL player, pleaded not guilty on Dec. 6, to charges of murdering his mother. The body of his mother, Myrtle Brown, was found on Sept. 16 and her son has been charged with first-degree murder and concealing a homicide.

According to The Chicago Sun-Times, Brown gave his plea in a Maywood courtroom in front of Cook County Judge Geary Kull. Brown was allegedly the last person to see his mother, who was 73 years old, as the two lived together. He was seen burning fabric on the night that she died on Sept. 14, according to prosecutors. He traveled to Cancun, Mexico, the next day after purchasing a one-way ticket.

Myrtle’s body was found on Sept. 16 wrapped in a sheet in tall grass less than 200 feet from the home they shared. She was discovered near a creek about 12 miles west of Chicago. A Cook County medical examiner determined that she suffered several injuries from being assaulted. She died from blunt force trauma, and her death was ruled a homicide.

Sergio was arrested on Oct. 10 after he had been partying in Mexico after his mother died. According to an unidentified law enforcement report by CNN, Sergio was taken into custody near San Diego after an arrest warrant had been issued in Illinois for the former New England Patriots player.

Brown played football while attending Proviso East High School in his hometown of Maywood before graduating to play his collegiate career at Notre Dame between 2006 and 2009. He played in the NFL as an undrafted player who was signed by the New England Patriots in 2010. He then went out to play with the Indianapolis Colts and the Jacksonville Jaguars before being signed by the Atlanta Falcons. After seven days, on August 27, 2016, the Falcons released him, and several months later he was picked up by the Buffalo Bills, where he ended his career.