D.J. attended Independence High School in Bakersfield, California. In his high school football career, he totaled six interceptions and five forced fumbles along with 1,150 total yards of offense with 13 touchdowns. Along with football, he also played basketball, and was the first person in school history to be named MVP in both sports.

As a freshmen, he redshirted at Fresno State. He then transferred to Cerritos College, a community college in Norwalk, California. After a year at Cerritos, he then transferred to Kansas State. 

As a redshirt sophomore in 2016, Reed played in all 13 of Kansas State's games as both a cornerback and a return specialist. Defensively, Reed totaled 75 tackles, 16 pass deflections and two forced fumbles. Offensively, he returned nine kickoffs for 255 yards. After the season, he was named to the 2016 All-Big 12 Conference football team.

Prior to the 2017 season, Reed was named to the Chuck Bednarik Award watch list, the Jim Thorpe Award watch list and the Bronko Nagurski Award watch list. In 11 games in 2017 he made 47 total tackles along with four interceptions, nine pass deflections and one forced fumble along with returning 17 kickoffs for 253 yards and one touchdown. After the conclusion of the season, he was named to the 2017 All-Big 12 Conference football team. He just recently declared for the 2018 NFL Draft.

D.J.'s journey to the NFL shows true patience and trust in the process, which is why he lives by the phrase, In Due Time.