The Illinois Supreme Court reversed a domestic battery conviction Thursday because the Cook County Circuit Court failed to administer a trial oath to the jury, calling it a grave error that “threatens the integrity of the judicial process.” Illinois Supreme Court Justice David K. Overstreet delivered the unanimous judgment of the court, with opinion. The case was remanded for a new trial.Chief Justice Anne M. Burke and Justices Rita B. Garman, Mary Jane Theis, P. Scott Neville, Jr., Michael J. Burke, and Robert L. Carter …