As a true freshman at Alabama State in 2018, Jefferson posted 12 receptions for 115 yards and four touchdowns, leading the team in the latter category.[4] The following year, he posted 49 receptions for 767 yards and 12 touchdowns; his touchdown total tied a team record.[5][6] In the COVID-19-shortened 2020 season, Jefferson tallied a team-leading 24 catches for 234 yards and two touchdowns.[5] After the year, he transferred to Louisiana.[5]
In his first year at Louisiana, Jefferson recorded a team-leading 481 receiving yards despite only placing sixth on the team with 18 catches, scoring four touchdowns on the season and being named honorable mention all-conference.[1][6] In the 2022 season, he posted 51 catches for 810 yards and seven scores.[7]
Jefferson had been projected as a potential middle-round selection in the 2023 NFL draft.[7] On April 11, 2023, he was severely injured in a car crash that killed another driver and needed multiple surgeries.[10][11] He was released from the hospital on April 19 and is slated to miss the entire season as a result of the crash.[12]