Lemuel Prion became Arizona's eighth exoneration in 2003 when it was shown that prosecutors ignored evidence that pointed towards another suspect in the murder and relied on testimony from a man that at the time of the murder could not identify Prion, but 17 months later identified him from a newspaper photo that Identified Prion as the prime suspect.

Arizona executed two German citizens in 1999, Karl and Walter LaGrand.Walter was executed by the gas chamber at his own election.Germany challenged the executions in the International Court of Justice (ICJ) in The Hague.The ICJ ruled that the executions should be stayed, but to no avail.

In 2002 by a 7-2 decision in Ring v. Arizona, the United States Supreme Court ended the practice of having a judge decide the eligibility for a death sentence in a death penalty case, as it violated a defendant's right to a trial by jury.