The State has the burden of proving the defendant guilty beyond a reasonable doubt under the law. The State has certain legal tools at its disposal to prove a defendant guilty: the subpoena power to force witnesses to come to court, the power to motion for a continuance, and the power to dismiss the case (stricken on leave or nolle prosqui) and then refile it against the defendant. But that power is balanced by the defendant's rights and the the Judge's rulings. When the State is forced to proceed to trial when they are not fully ready, due to the Judge's rulings and/or in fairness to the defendant's rights, another tactic that prosecutors employ is to present no evidence (because they have no witnesses available), and then later argue they were not able to try the defendant. The State then argues the prosecution should be given another chance to prove the defendant guilty at trial. The United States Supreme Court overruled the Illinois Supreme Court and held that the State cannot retry the defendant under these circumstances.