In United States v. Louis Mayrand, the Supreme Court considered whether a defendant could be convicted of counterfeiting without proof that he had knowledge of the counterfeit nature of the notes in his possession. The case arose when Louis Mayrand was arrested for having counterfeit notes in his possession and charged with violating federal laws prohibiting counterfeiting. At trial, there was no evidence presented to show that Mayrand knew or should have known that the notes were counterfeit; however, he was still found guilty by a jury and sentenced to two years' imprisonment. On appeal, Mayrand argued that conviction required proof beyond reasonable doubt as to both criminal intent and knowledge of the character of what is possessed; otherwise it would be an unconstitutional deprivation of liberty without due process under law. The Supreme Court agreed with this argument and reversed his conviction on grounds that knowledge must be proven before one can be held criminally liable for possessing something which turns out to be illegal or prohibited by law.

In United States v. Louis Mayrand, the Supreme Court was asked to decide whether a person who had been convicted of treason in Canada and then escaped to the United States could be extradited back to Canada for punishment. The majority opinion held that extradition was permissible under international law and did not violate any constitutional rights of the accused. However, Justice Field dissented from this ruling, arguing that there is no provision in either U.S or Canadian law which allows for extradition between two countries when one has already tried and punished an individual for a crime committed outside its own borders. He argued further that allowing such extraditions would lead to double jeopardy as well as other violations of due process rights guaranteed by both nations' constitutions. In conclusion, he concluded that while it may be possible under certain circumstances for one country's laws to apply extraterritorially within another nation's jurisdiction, this case did not meet those criteria and thus extradition should not have been allowed here