Riley attended Stephenson High School in Stone Mountain, Georgia, where he, besides occasionally lining up at running back and strong safety, was part of a highly talented linebacker corps with teammates Kelvin Sheppard, Marcus Ball and Jermaine Cunningham.

As a sophomore, he played all 14 season games for the Tigers and tallied 24 tackles, including 1.5 for losses and a half quarterback sack.

Riley recorded two solo tackles in the 2008 BCS National Championship Game versus Ohio State.

A starter in his junior year for the Tigers, Riley ranked among the team leaders in total tackles with 60, including 7.0 for losses and 1.5 sacks.

Riley finished the season playing all 16 games, starting eight of them, and recording 68 combined tackles, one sack, and four pass breakups.

In Week 2 against the St. Louis Rams, he recorded his first career forced fumble from wide receiver Danny Amendola, which was recovered by Josh Wilson and returned 30 yards for a touchdown.

He recorded his first career interception on Kansas City Chiefs backup quarterback Chase Daniel in a Week 14 loss.