In the case of Jones v. United States in 1921, the Supreme Court ruled that a defendant cannot be convicted for both conspiracy to commit a crime and the actual commission of that crime if it is proven beyond reasonable doubt that he did not personally commit any overt act in furtherance of the conspiracy. The court held this view even though an accomplice may have committed such an act. This decision was based on Section 37 of the Criminal Code which requires proof that one conspirator has committed at least one overt act towards accomplishing their illegal objective for all members to be guilty. In essence, this ruling clarified how complicity and personal responsibility are determined within criminal law.

In the dissenting opinion for Jones v. United States, Justice McReynolds disagreed with the majority's interpretation of the National Prohibition Act. He argued that Congress did not intend to criminalize all possession of alcohol, but only possession intended for illegal uses such as sale or distribution. According to him, interpreting the law in this way would make it a crime for someone to possess liquor even if they had no intention of selling or distributing it and were using it solely for personal use which was not prohibited by any state law at that time. This interpretation could potentially infringe upon an individual’s rights under certain circumstances where there is no intent to violate prohibition laws. Therefore, he believed that Mr.Jones should have been acquitted because there was insufficient evidence proving his intent to sell or distribute alcohol illegally.