As a senior, he contributed to his team's undefeated record in the Chicago Public League’s Intra-City Central Conference.

As a senior in 2008, he started all 11 games at weakside linebacker, posting 67 tackles (39 solo), four sacks, 14.5 tackles-for-losses and led the nation with a school-record six forced fumbles.

He became the first player in school history to earn repeated All-American honors, he was also named the team's Defensive MVP and played in the East-West Shrine Game.

He recorded a career total of 289 tackles, 15.0 sacks (10th in school history), 45 tackles-for-loss (seventh in school history), 14 forced fumbles (tied NCAA record), 12 pass breakups, one interception, two fumble recoveries, and one blocked kick while starting 35-of-43 games.

Williams was not invited to participate at the 2009 NFL Scouting Combine, however he did take part in Northwestern University's Pro Day.

[2] After posting great pre-draft numbers, the Cowboys surprised observers by selecting Williams in the third round (69th overall).

[3] In 2010, during a 1–7 start, the Cowboys declared him inactive for two games because of poor play, before releasing him on November 2, based on his inability to grasp the defense and a lack of consistency on special teams.

He recorded five tackles, one fumble recovery and two passes defended in two games as a starter at weak-side linebacker.

[10] On October 16, the Panthers re-signed him to take over Chase Blackburn's special teams duties, after he was named the starter at weakside linebacker.

[12] On December 8, 2014, he was signed as free agent by the Tampa Bay Buccaneers, after Brandon Magee was placed on the injured reserve list.