Vonte (vonn-TAY') Skinner was convicted of shooting a rival in 2005, leaving the man partially paralyzed.
During his trial, prosecutors read 13 pages of rap lyrics attributed to Skinner. The lyrics, many describing violent acts, were written three or four years before the shooting.
An appeals court overturned the guilty verdict, writing that caution must be exercised when allowing prior writings as evidence in a trial.
The Supreme Court justices on Wednesday questioned attorneys for the state how the lyrics could be used as evidence when they didn't describe the actual crime and were written years before.