He attended Princeton Day Academy in Lanham, Maryland, and was a highly scouted prospect for the 2013 college recruiting class.
In January 2012, Carr announced his commitment to the Seton Hall University Pirates men's basketball team for the 2013–14 season.
[4] The following week, Carr received the honor again after he scored 15 of his 38 points in the fourth quarter against defending Class 2A state champions, Baltimore City College.
[7] During his sophomore season, he scored 57 points against Forest Park to win the Big Miller Christmas Classic, 103–71.
[6] Carr led his team to a school-best 25–2 record and the Class 4A state championship game, where they incurred their second loss.
[11] Patterson relocated from its small gymnasium to the arena on the Morgan State University campus eight times during the season to hold the large crowds drawn to attend his games.
[12] Shortly after the tournament, the Italian professional basketball club Lottomatica Roma reportedly offered Carr, a high school sophomore at the time, a $750,000 contract.
[15] Carr played with the Under Armour-sponsored Baltimore Elite Amateur Athletic Union team.
[16][17] On November 23, 2013, in his debut game, Carr recorded 15 points and 2 assists in a 106–117 loss to the Canton Charge.
On September 9, 2014, Carr signed a one-year deal with the Saint John Mill Rats of the Canadian National Basketball League.
[9][12] However, he reportedly measures a 48-inch vertical leap, has excellent ball-handling skills, which allow him to create space for his shot,[9] and the athleticism to dunk despite his height.
[9] Sports Illustrated wrote, "He has explosive speed, electric ball-handling skills and court vision that could rival Steve Nash's.
"[6] ESPN wrote that he is "one of the quickest and [most] explosive players in the country, regardless of class", but noted his inconsistent jump shot and turnovers were areas for improvement.