A champion at every level so far, Riker sprang a surprise to wint the National Championships in 2011 in a personal best time of 45.30 seconds.  That win elongated a bright resume that included a 2007 win for St. Jago High School at the Jamaican high school championships and a junior college title for Essex County College in the USA.

In his years as a junior, he gained international experienceat the 2007 Pan-Am Junior Championships where he just missed a medal.

While at Louisiana State University, Riker was an indoor NCAA finalist and set an undercover personal best of 46.33 seconds.