At Boyle's trial, the state demonstrated that Boyle and others had committed a series of bank robberies in four states during the 1990s. A core group was involved in all the robberies, but sometimes others would also assist them. The group would meet before each crime to plan the robbery, assign everyone's tasks, and assemble the tools. After each heist, they would divide the proceeds. There was no clear leader and no overall master plan for a series of robberies.

At the trial, the judge told jurors that to establish the existence of an enterprise, the government had to prove that "(1) there [was] an ongoing organization with some sort of framework, formal or informal, for carrying out its objectives; and (2) the various members and associates of the association function [ed] as a continuing unit to achieve a common purpose." The judge also told the jury that it could "find an enterprise where an association of individuals, without structural hierarchy, [was] form [ed] solely for the purpose of carrying out a pattern of racketeering acts," and that "[common sense suggests that the existence of an association-in-fact is oftentimes more readily proven by what it does, rather than by abstract analysis of its structure."

The judge did not give the jury Boyle's requested instruction that the government was required to prove the enterprise "had an ongoing organization, a core membership that functioned as a continuing unit, and an ascertainable structural hierarchy distinct from the charged predicate acts."

After Boyle was convicted of 11 of 12 counts against him, including the RICO counts, and was sentenced to prison, he appealed on grounds that the instructions about what would constitute proof of an enterprise incorrectly set forth the law. The circuit court affirmed his convictions, and he appealed to the U.S. Supreme Court. How do you think the high court ruled and why?

[ Boyle v. United States, 129 S. Ct. 2237 (U.S. Sup. Ct. 2009)