Track athlete who won two gold medals at the 2004 Athens Olympics and one gold and one silver at the 2008 Beijing games.
He attended Baylor University, where he was coached by the famous Clyde Hart.
He won several world championships, including golds at Helsinki in 2005, at Osaka in 2007, and one gold and one silver in 2009 at Berlin.
He married Sarah Nichols in 2011.
He became the third-fastest runner of all time in the 400m in 2007 at Osaka, trailing Michael Johnson and Butch Reynolds' records.