The Sixth Amendment to the U.S. Constitution provides in pertinent part: The Sixth Amendment guarantees a speedy and public trial by impartial jury of one s peers, the right to have and to compel the testimony of witnesses, and to have the assistance of counsel in all criminal prosecutions. One of the most controversial contributions of social science to criminal justice procedure has been recent attempts at "scientific selection" of juries. Such use may endanger the entire concept of an "impartial" jury.