In the 1953 case Pereira et al. v. United States, the U.S Supreme Court ruled on a matter involving mail fraud and money laundering charges. The defendants were convicted of using mail to defraud and for conspiring to launder money obtained through illegal means in violation of federal law. They appealed their convictions arguing that they had not used mails "for the purpose" of executing such scheme as required by statute, but rather incidental use was made after obtaining funds unlawfully from victims. The Supreme Court upheld their convictions stating that if one intentionally uses mails in furtherance of fraudulent scheme then it is immaterial whether mailing occurred before or after securing proceeds from victims; what matters is its part in execution of scheme itself. Furthermore, court held that conspiracy charge was valid even though no specific intent to violate particular provision (money laundering) was shown; agreement need only be aimed at unlawful objective with knowledge that some form aiding/abetting would follow.

In the dissenting opinion for Pereira et al. v. United States, Justice Jackson disagreed with the majority's interpretation of "in furtherance" in relation to mail fraud statutes. He argued that this interpretation was too broad and could potentially criminalize any use of mails after a fraudulent scheme has been executed, even if it did not directly contribute to the execution or concealment of said scheme. Furthermore, he contended that such an expansive reading would make these statutes overly punitive and might lead to their misuse by prosecutors seeking harsher penalties for defendants who had already completed their fraudulent activities before using mails. In his view, only those uses of mails which actively facilitate or hide a fraud should be considered as being "in furtherance" under these laws.