[2] As a freshman in 2008 at Independence Community College, Lamur had 45 tackles in nine games, with one sack and two interceptions, earning an All-Conference second-team selection.

[6][7] During training camp, he competed for a roster spot as a backup outside linebacker against Dontay Moch, Micah Johnson, Dan Skuta, and Brandon Joyner.

[10] On November 2, 2012, he was promoted to the active roster after the team placed Dontay Moch on the season-ending reserve non-football injury list.

[9] Head coach Marvin Lewis named Lamur the fifth outside linebacker on the depth chart, behind Manny Lawson, Vontaze Burfict, Dan Skuta, and Vincent Rey.

[11] The following Sunday, November 4, 2012, Lamur made his professional regular season debut and recorded three combined tackles and broke up a pass during a 31–23 loss to the Denver Broncos in Week 9.

[12] During training camp in 2013, Lamur competed for a job as a backup outside linebacker against Aaron Maybin, Sean Porter, Jayson DiManche, Vincent Rey, Brandon Joiner, and Bruce Taylor.

[14] On August 30, 2013, Lamur was carted off the field due to a shoulder injury he suffered while tackling Donald Brown in the Bengals' 27–10 win against the Indianapolis Colts on their fourth preseason game.

[22] He finished the 2014 NFL season with 91 combined tackles (53 solo), seven pass deflections, two interceptions in 14 games and 13 starts.

[13] In 2015, Lamur played in the first six games of the season, collecting 19 tackles, a shared sack, one pass defended and a special teams fumble recovery.

In Week 2 against the San Diego Chargers, he recovered a muffed punt by Keenan Allen in the first quarter that set up a Bengals touchdown for a 7–0 lead.