He played in three different high schools in Alabama, spending his senior year at Central Park Christian Academy, where he was one of the top players in the nation in the class of 2001.
He went undrafted in the 2006 NBA draft and started his professional career in Europe with Turkish team Darüşşafaka.
Throughout his career he has played in Estonia, France, Israel, Italy, Puerto Rico, Russia, South Korea, Turkey and Ukraine.
Killingsworth was born in Montgomery, Alabama to father John and mother Johnnie Mae (née Hooks).
[1][3] In his senior season at Central Park, Killingsworth averaged 30 points, 13 rebounds and 7 blocks per game while shooting 67% from the field.
[1] He was named in the All-State First Team and he was ranked the second best player in the state of Alabama behind Ousmane Cisse of St. Jude Educational Institute.
[8] Hoop Scoop ranked him 40th overall,[9] and he was the 53rd best player of his class according to the Recruiting Services Consensus Index (RSCI).
He received offers from Alabama, Auburn, Cincinnati, Florida, Georgia Tech, Indiana, LSU, Tennessee and UConn.
[11][12] Killingsworth chose to wear jersey number 4 at Auburn, and head coach Cliff Ellis gave him considerable playing time in his freshman year.
[1] He had a season-high 9 rebounds against LSU, and he scored a season high 17 points on December 20, 2001, against UNC Asheville in 16 minutes of playing time.
[3] In the summer of 2004, Killingsworth declared himself eligible for the 2004 NBA draft as an early entrant, but he did not hire an agent and later withdrew his name.
On November 30, 2005, Killingsworth scored 34 points and posted 10 rebounds against #1 Duke, being defended by highly regarded player Shelden Williams during the ACC–Big Ten Challenge.
He also had the chance to play in the NCAA Tournament for the second time in his career, and started both games (against San Diego State and Gonzaga).
He then moved to Maccabi Haifa, where he played 20 games in the first half of the 2010–11 season, earning his first All-Star selection with averages of 17.1 points and 7.3 rebounds.
He then went back to Israel, signing with Ironi Ashkelon, where he spent the full 2011–12 season, averaging 16.2 points and 7.4 rebounds and earning his second All-Star game appearance.
In 27 games he averaged 17.4 points (his career high in Israel) and 7.8 rebounds during the 2012–13 Israeli Basketball Super League season.