BBC News By Robin Levinson-King image copyrightGetty Images image captionSha'Carri Richardson was banned for cannabis use, despite winning the US trials for her event US sprinter Sha'Carri Richardson will be missing the Tokyo Olympics because she tested positive for marijuana during the US Track & Field trials. With cannabis legal in many states across America, why is it still outlawed in sports? With her flowing tangerine orange hair, killer smile and lightning speed, Sha'Carri Richardson was unmissable in the lead-up to the Olympic Games. Considered the sixth-fastest woman in history, with a best-ever time for the 100m of 10.72, the Texas sprinter was expected to be a major contender for the Gold medal in Tokyo.