He played college football for the North Carolina Tar Heels and was selected by the New York Giants in the second round of the 2011 NFL draft.

[1] As a junior in 2005, he helped Coolidge to the D.C. Interscholastic Athletic Association title game for the first time since 1986,[2] where they lost 43–14 to a Dunbar team that was led by Arrelious Benn, Nate Bussey, and Vontae Davis.

Austin contributed 85 tackles and 17 sacks, and was named High School All-Metro First-team by Washington Post for consecutive times (2005 and 2006).

[7] He was recruited by numerous top programs around the country including Florida State, Southern California, and Tennessee.

[9] Austin along with Tar Heels pass rusher Robert Quinn, receiver Greg Little and three others were suspended the entire 2010 season.

He scored a touchdown by recovering a fumble by Texas A&M Aggies' starting quarterback Jerrod Johnson 3 yards out of the endzone.

[13][14][15] Giants general manager Jerry Reese stated he consulted Austin's teammate at UNC Hakeem Nicks prior to the selection.

[16] Bears coach Lovie Smith and defensive coordinator Rod Marinelli visited Austin and "spent a goodly amount of time with him".

[16] On August 22, Austin's season was cut short as he tore his pectoral muscle during a preseason game against the Bears.

Due to a back injury suffered during practice, Austin missed the Cowboys' next game against the Minnesota Vikings, and was cut two days later, on November 5, 2013.