The case of Pinkerton et al. versus the United States involved two defendants who were found guilty of violating the Internal Revenue Code and sentenced to imprisonment and fines. The Supreme Court ruled that the substantive offenses were separate and distinct from the conspiracy count and could not be merged. A conviction for conspiracy can still be obtained even if the substantive offense was completed, and the plea of double jeopardy is not a defense to a conviction for both offenses, as long as there is no identity of offenses. Evidence of direct participation or other evidence from which participation can be inferred is not necessary to sustain a conviction for a substantive offense committed in furtherance of a conspiracy. In a continuous conspiracy, all members are responsible for the substantive offense committed by one of the conspirators in furtherance of the unlawful project. Justice Rutledge dissents and believes that the judgment concerning one of the defendants should be reversed because there was no evidence that he participated in the substantive offenses committed by his brother.

The court should be cautious in treating conspiracy, aiding and abetting, and substantive crime as identical. Daniel's conviction for substantive crimes committed only by Walter should be reversed because there was no evidence that he counseled, advised, or had knowledge of those particular acts or offenses. The court's theory of vicarious criminal responsibility is dangerous and results in either attributing Walter's guilt to Daniel or punishing him twice for the same offense. The government's technical variations in the indictment should not be allowed to achieve so much. Walter should still be convicted of the substantive offenses, but his sentence for conspiracy should be annulled. Daniel's sentence on all counts should also be annulled. Justice Frankfurter agrees with the dissent's views but is reserving judgment on the double jeopardy question.