His college career was marked by many memorable overtime performances, game-winning shots and game-clinching free throws.

[9] He was also selected to participate in the Rodney Beasley East vs. West All-Star Games, sponsored by the Baltimore Metro Coaches Association.

[10] He was also a second team All-metro selection and following his 1992 graduation attended the Fork Union Military Academy in Virginia for a postgraduate year.

[12] Johnson showed strong leadership skills early at Princeton and is the only three-time captain in university history.

At the end of the third overtime period Johnson converted two foul shots with three seconds left to cement a 71–66 victory over Texas A&M.

[17] As a junior, he was named Ivy League Player of the week for the second weekend in February as he led the team on both ends of the court.

[17] After Princeton and Penn ended the 1995–96 season tied as Ivy League Co-Champions, Johnson made the decisive three point shot with one minute and four seconds remaining in overtime in the one-game playoff, corralled a defensive rebound, added a pair of free throws with 24 seconds left and then made a steal.

[25] The win earned the team the conference automatic bid to the 1996 NCAA tournament and following the game head coach Pete Carril announced his retirement.

[32] The following week, he established Ivy League records for most consecutive three-point field goals made, with 11, and the most single-game three-point field goals made with no misses (6 for 6) against Columbia Lions men's basketball on February 28, 1997, and Cornell Big Red men's basketball (first 5) on March 1, 1997.

[20][33][34] He had twelve points in the regular season finale during which Princeton tied the school record with its nineteenth consecutive win.

[35] In the 1997 NCAA tournament opening round matchup against the Cal Bears, when a final second pass was intercepted, he attempted to shoulder the blame with the press.

[38][39] As of February 12, 2024[update], Johnson's 11 consecutive three-point shots record stood alone in Ivy League history, but 3 subsequent players had tied his 6–6 single-game performance (Christian Webster — Harvard -vs- Appalachian St., March 27, 2010; Siyani Chambers — Harvard -vs- Vermont, Dec. 21, 2013; Devin Cannady — Princeton -vs- Fairleigh Dickinson, Nov. 26, 2017).

[40] After writing his senior thesis on Kenyan education under British colonial rule and graduating with a bachelor's degree in history, Johnson declined the postgraduate scholarship that he was awarded and played five years in Italy followed by two in Spain.

[1] Johnson played professional basketball in the Lega Basket Serie A and Legadue Basket in Italy and Liga Española de Baloncesto in Spain, one season each for Gorizia Pallacanestro A2, Viola Reggio Calabria, Adecco Milano/Ducato Siena, Casademont Girona and Montepaschi Siena.

[17] Johnson was then brought on as an assistant to the newly appointed head coach at Georgetown, John Thompson III, in 2004.

[47] During his tenure at Georgetown, he helped coach the team to an overall 72–30 record over 3 seasons and the 2006–07 team the 2007 Big East regular season championship, the 2007 Big East men's basketball tournament championship, and a trip to the Final Four of the 2007 NCAA Division I men's basketball tournament.

[41][48] When Scott abandoned his struggling Princeton team to coach at Denver in 2007, athletic director Gary Walters hired Johnson to take over the program.

[49][50] Johnson emerged from a field of Princeton offense veterans that included Mike Brennan, Robert Burke, Craig Robinson, Bill Carmody, Armond Hill, Chris Mooney, and Mitch Henderson.

[51] Johnson's demeanor as a coach was said by players to be more benevolent than his predecessor, Joe Scott, who left for the University of Denver after compiling a losing record in three years at Princeton.

[60] During Johnson's third season, the 2009–10 team rebounded from a 2–4 start to win 20 of its final 25 games and earn a berth in the 2010 College Basketball Invitational.

[63] The Tigers had previously won in the postseason in Indianapolis when the Johnson-led 1995–96 team pulled off a first round upset of the national defending champion UCLA in the 1996 Tournament.

[67] In 2010, Johnson tweaked the motion Princeton offense to be a bit more uptempo, resulting in more possessions and higher scores.

[69] On March 8, Princeton defeated Penn to force a one-game playoff at the Payne Whitney Gymnasium in New Haven, Connecticut.

[76] In April 2011, Johnson accepted a head coaching position at Fairfield University, replacing Ed Cooley.

[77][78] He coached the 2011–12 Stags to the semifinals of the 2012 CollegeInsider.com Postseason Tournament where they lost to Mercer, after defeating Yale, Manhattan and Robert Morris to finish with a 22–15 record.

[85] Johnson was named associate head coach on former Princeton basketball player Joe Scott's staff at Air Force for the 2020–21 season.

[17] Johnson had been very involved with the university as a whole during his head coaching career, participating in a task force charged with surveying the impact of Princeton's eating clubs on campus life, and sitting with his players in the student section at many home football games.