What is the test for a jury to convict a defendant of aggravated murder?

Furthermore, the court instructed the jury that to find a defendant guilty of aggravated murder, it must find beyond a reasonable doubt "that an act or an element of the offense was committed in Multnomah County, Oregon" and that "either the robbery or the homicide commenced in Oregon." The court similarly instructed the jury for the felony murder charge. It is presumed the jury followed the instructions. United States v. Van Cauwenberghe, 827 F.2d 424, 432 (9th Cir.1987), cert. denied, 484 U.S. 1042 (1988).