Richardson was selected with the ninth pick of the second round in the 2006 NBA D-League Draft by the Fort Worth Flyers. On January 27, 2007, he was signed to a ten-day contract by the Atlanta Hawks. Previously playing for the Flyers, it was the seventh call-up from the D-League during the 2006–07 season.[3] After his second 10-day contract[4] expired, the Hawks opted not to retain him.
In March 2007, he was signed to a 10-day contract by the Portland Trail Blazers.[5] At the end of the contract, the Blazers cut him; he played in one game for them.[6] Richardson returned to the Flyers afterwards.
Richardson spent the 2007-08 NBA preseason with the Miami Heat but was waived on October 29, 2007.[8] On December 20, 2007, he was signed by the Memphis Grizzlies.[8][9] Until then he was averaging 28.5 points, 6.6 rebounds, 1.8 assists and 1.63 steals[8] in 41.5 minutes in eight games for the Mad Ants. He was named D-League.com Performer of the Week, after averaging 35 points, 6.5 rebounds, and 4.0 assists in two games during the week of December 3, shooting 53.2% from the field (25/47), including scoring a league season-high 40 points against the Iowa Energy on November 29.[7] He was waived on January 7, and signed three days later with the San Antonio Spurs.[8]
In 2008, Richardson was named MVP of the D-League All Star Game, scoring 22 points on 9/15 shooting. Shortly afterwards, he was signed to another 10-day contract by the Atlanta Hawks. Richardson in the 2008 offseason was signed by the Orlando Magic. On December 8 he received a 3.5 million dollar bonus.
In August 2011, he signed with BC Armia in Georgia.[12] In August 2012, he joined Sidigas Avellino in Italy.[13] In September 2013, he re-signed with Avellino for one more season.[14]
In July 2014, he signed a one-year deal with Enel Brindisi.[15] He parted ways with club before the start of the new season, because of personal reasons.[16][17]
