Following his college career, Crum played for the Sacramento Mountain Lions of the United Football League and was signed as an undrafted free agent in 2009.
Crum would return to his alma mater for one season in 2015, serving as a defensive graduate assistant at Notre Dame under head coach Brian Kelly.
He would move on to Indiana State for one season, serving as the Sycamores' defensive back coach.
Crum would be promoted to head defensive coordinator in 2021 after incumbent DC Clayton White was hired for the same position at South Carolina.
[1] In 2022, Crum was hired as a co-defensive coordinator at Ole Miss and also served as the Rebels' linebackers coach.