As a senior for the Pirates, Pierce earned All-CIF Southern Section Division 2 accolades at linebacker while also playing at the fullback position.

[2][3] He then played two years of football at Mount San Antonio College in Walnut, California, before transferring to the University of Arizona.

SAC to the CCCAA state title, intercepting a pass for the Mounties in the fourth quarter of a 38–35 win over San Francisco City College.

[4] As a senior at Arizona, he had three sacks, 77 tackles (ten for losses), two forced fumbles, one interception, and one blocked kick, earning All-Pac-10 honorable mention.

He also had one forced fumble, one sack, and two interceptions, including a pick off Ken Dorsey returned 76 yards for a touchdown.

He became the captain of the defense, and in 13 games, Pierce notched 100 tackles, 80 of them solo, two interceptions, and one forced fumble returned for a touchdown.

[9] On the early morning hours of November 9, 2008, at a night club in New York City, Plaxico Burress accidentally discharged an unlicensed gun in his pocket, injuring his thigh.

The struggles continued in 2016 and 2017, with the program failing to reach double digit wins in both years and getting blown out in the playoffs.

After two seasons as the Sun Devils' linebackers coach, Pierce was promoted to co-defensive coordinator alongside Marvin Lewis.

[14] On January 20, 2021, Pierce was elevated to be the sole defensive coordinator at ASU after sharing the role with Marvin Lewis during the 2020 season.

[16] In August 2023, ASU announced a self-imposed bowl ban, hoping to lessen further penalties resulting from the ongoing investigation.

[21] In a statement regarding the penalties, ASU president Michael M. Crow declared the university to be, "disappointed and embarrassed by the actions of certain former football staff members who took advantage of a global pandemic to hide their behavior.

[24] He named Aidan O'Connell as the starting quarterback for the rest of the season on November 1, benching Jimmy Garoppolo.

Inspired by his own experiences growing up in Compton, it has become Pierce's mission to improve the quality of life for the youth in the Long Beach/Compton area.

[citation needed] In 2006, Pierce became the spokesperson for Giants Academy—a program for inner city youth geared toward helping these children succeed despite obstacles in their life.

Pierce was present when teammate Plaxico Burress negligently shot himself in the thigh at the Latin Quarter Night Club in New York City on November 28, 2008.