He played college football for the Grand Valley State Lakers and was selected by the Chiefs in the fifth round of the 2008 NFL draft.

During his sophomore and junior seasons, he helped the Lakers win back-to-back NCAA Division II Football Championships.

[1] Carr did not receive an invitation to the NFL Scouting Combine or to any All-Star games due to his limited exposure attending Grand Valley State.

On March 10, 2008, Carr attended Central Michigan's pro day and performed the majority of drills, but opted to skip the bench press.

[2] At the conclusion of the pre-draft process, Carr was projected to be a sixth or seventh-round pick by NFL draft experts and scouts.

[8] Head coach Herman Edwards named Carr the third cornerback and first-team nickelback to start the regular season, behind Patrick Surtain and Brandon Flowers.

[9][10] Carr made his NFL debut and first career start in the season-opener at the New England Patriots and recorded three combined tackles in their 17–10 loss.

On September 21, 2008, Carr earned his first start as an outside cornerback after Patrick Surtain injured his shoulder the previous week against the Oakland Raiders.

[12] Carr finished his rookie year with 73 combined tackles (70 solo), six pass deflections, two interceptions, and two fumble recoveries in 16 games and starts.

[14] Carr and Flowers entered training camp slated as the starting cornerbacks under new defensive coordinator Clancy Pendergast.

[15] Head coach Todd Haley officially named Carr and Flowers the starting cornerback duo to begin the regular season.

In the regular-season finale, Carr recorded two combined tackles, deflected two passes, and an interception in the Chiefs' 7–3 win at the Denver Broncos in Week 17.

He intercepted Tim Tebow's pass that was intended for Eddie Royal and sealed the Chiefs' victory on the last defensive play in the fourth quarter.

[27] Head coach Jason Garrett officially named him the starter to begin the regular season, alongside rookie Morris Claiborne and ahead of Orlando Scandrick and Mike Jenkins.

[28] On November 11, 2012, Carr recorded four solo tackles, a pass deflection, and returned an interception for his first NFL touchdown during a 38–23 victory at the Philadelphia Eagles in Week 10.

Defensive coordinator Monte Kiffin retained Carr and Claiborne as the starting cornerbacks after Rob Ryan was fired after the 2012 season.

[32] He started in the Dallas Cowboys' season-opener against the New York Giants and recorded four solo tackles, broke up a pass, and returned an interception for a touchdown in a 36–31 victory.

The interception occurred off a pass attempt by Eli Manning that was intended for running back Da'Rel Scott and returned it for a 49-yard touchdown in the fourth quarter.

Head coach Jason Garrett opted to retain Carr and Claiborne as the starting cornerbacks duo with Orlando Scandrick as their nickelback to begin the season.

[35] On October 5, 2014, Carr collected a season-high eight combined tackles and deflected a pass in the Cowboys' 20–17 loss to the Washington Redskins in Week 8.

On January 4, 2015, Carr started in the NFC Wildcard Game and recorded six solo tackles and a pass deflection during the Cowboys' 24–20 win against the Detroit Lions.

[36] The following week, he made three solo tackles as the Cowboys were eliminated from the playoffs after losing 26–21 at the Green Bay Packers in the NFC Divisional Round.

[13] He had a career resurgence in 2016 after defensive coordinator Rod Marinelli moved him to play the right outside cornerback position, where he experienced success with during his first four years in Kansas City.

On January 15, 2017, Carr made three solo tackles as the Cowboys narrowly lost 34–31 to the Green Bay Packers in the NFC Divisional Round.

[47] Carr finished the 2017 season with 56 combined tackles (50 solo), 12 pass deflections, and tied his career-high with four interceptions in 16 games and starts.