In 2005, he was involved in an incident with Virginia offensive tackle Brad Butler, who hit Kiwanuka with a chop-block in the back of his leg several seconds after the whistle.

Kiwanuka was forced to miss Boston College's next game because of injury, and Butler received a one-game suspension.

[1] He was a First-team All-American in 2004 and was named Big East Defensive Player of the Year in 2004, as he produced 11.5 sacks, 24.5 stops for losses and 67 tackles (36 solo).

[7] Kiwanuka's season ended at Detroit on November 18, 2007, when he suffered a fractured left fibula.

He had surgery to stabilize his leg and ankle the following morning and was placed on Injured Reserve, ending his 2007 season.

He started all 10 games in which he played and finished the season with 47 tackles (24 solo), 4.5 sacks, 4 passes defensed, 1 forced fumble.

In 2008, Kiwanuka entered training camp as the starting strongside linebacker, but returned to defensive end when Osi Umenyiora suffered a season-ending knee injury during the preseason.

[9] He started all 16 games and the NFC Divisional Playoff game at right defensive end and finished the season with 59 tackles (28 solo), 8.0 sacks, 13 tackles for loss, 2 passes defensed, 2 forced fumbles and 2 fumble recoveries.

[13] The restructured deal, converted $1.5 million of Kiwanuka's 2013 guaranteed base salary into a signing bonus.