The U.S. Supreme Court's decision in Blakely v. Washington (June 24, 2004) influenced the Commission's work during the year. This is a landmark case that invalidated a sentence imposed under the sentencing guidelines statute of Washington State. The decision held that the judicial application of an enhanced range under the Washington State guidelines violated the defendant's sixth amendment right to a jury trial. Although the decision did not involve Federal sentencing guidelines, Federal circuit and district courts expressed varying opinions on the decision's implication for Federal sentencing. The Commission coded and assimilated the information from approximately 18,000 sentencings conducted after "Blakely." Because the mandatory nature of the guidelines was uncertain during the post-Blakely portion of fiscal year 2004, the Commission decided to create two datasets that analyzed the Federal sentences imposed in fiscal year 2004. The first dataset contains cases sentenced between October 1, 2003, and June 24, 2004, the date of the "Blakely" decision. From June 25, 2004, through September 30, 2004, courts arrived at significantly different conclusions regarding the continued viability of the guidelines, so the guidelines were not applied in a uniform fashion. Consequently, the Commission could no longer rely upon the assumption that the guidelines had been mandatorily applied. Accordingly, the Commission created a separate dataset for the post-Blakely cases. On November 1, 2003, the package of guideline amendments that had been submitted to Congress during the 2003 fiscal year went into effect. The commission continued its statutory mission to conduct guidelines training. More than 450 persons participated in the Thirteenth Annual National Seminar on the Federal Sentencing Guidelines. 113 notes