Mustapha began his collegiate football career at the University of Richmond in 2020, where he started all four games of the team's spring season and tallied 17 tackles. He later transferred to Wake Forest in 2021 and finished the season with 37 tackles (two for loss), one forced fumble, two fumble recoveries, four passes defended and two interceptions.
The safety went on to be named a team captain in his final season at Wake Forest (2023). He started in every game and finished the season as the team's leader in solo tackles (45). Throughout his three seasons playing at Wake Forest, Mustapha recorded 175 total tackles, 15 tackles for loss, 4.0 sacks, three interceptions, 10 passes defended, four forced fumbles and two fumble recoveries.