From the article:
According to the prosecution evidence, on March 23, 2006, Lewis was with co-defendant Jason Mantell Junious, 22, and an unidentified juvenile. They were driving around looking for someone to rob. Near 23rd and T streets they spotted Bowens. It was about 2 a.m.
They parked near Bowens and approached her. Lewis immediately shot Bowens in the back with a shotgun, then shot her again after she fell to the ground.