He has medaled at three World Championships, winning two Bronze, one Gold, and one Silver. He is currently the seventh fastest man ever, and is currently the fastest indoor runner in the United States. At the 2008 Olympics, he finished in third place, but was not given his medal because he stepped out of his lane at one point during the race. He, and the second place runner who also stepped out of lane, were disqualified, and the silver and bronze medals passed to the fourth and fifth runners.
