reeva steenkamp and oscar pistorius were a dazzling couple. she was a brilliant model. as an athlete famous for defying the odds. their futures glowed with promise. then reeva was gunned down. as police investigated, a chilling question transfixed the world. was her death an accident? or was south africa's national hero a murderer? here's keith morrison with "the rise and fall of oscar pistorius." keith morrison: such a time it was, like a different world looking back at this now. this was london. the year was 2012. and olympic history was about to be made. the moment was electrifying. in 45.44 seconds, a south african double amputee running on carbon fiber legs was transformed from global nobody to international superstar, with a superhero nickname, the blade runner. he was oscar pistorius. he was just this amazing, amazing icon. keith morrison: and in south africa, he was adored, not just as a remarkable athlete, but as a man of apparently flawless character, modest good manners, and many good works, irresistible. of course what with endorsements and all, he was almost