In the 1912 case of Charlton v. Kelly, Sheriff of Hudson County, New Jersey, the U.S Supreme Court ruled in favor of extradition. The case involved Porter Charlton who confessed to murdering his wife in Italy and then fled to America. Italian authorities requested his extradition under a treaty between Italy and the United States which allowed for such actions if evidence was sufficient according to American law standards. Charlton's defense argued that he should not be extradited because he was an American citizen and also claimed insanity at the time of murder; however, these arguments were rejected by lower courts. The Supreme Court upheld these decisions stating that nationality does not exempt someone from extradition under international treaties agreed upon by their country. Furthermore, they stated it is up to the foreign court where crime occurred (in this case Italy) rather than US courts or Secretary of State to decide on matters like criminal responsibility due mental illness during trial proceedings there.

In the dissenting opinion for Charlton v. Kelly, Justice Hughes argued that the extradition of Porter Charlton to Italy should not be allowed due to a lack of assurance from Italy that they would uphold their treaty obligations with the United States. He expressed concern over whether or not Italy would respect its agreement with the U.S., which stipulates that an extradited person can only be tried for crimes specified in their extradition request. Hughes believed there was no guarantee given by Italy that it wouldn't try Charlton for other offenses once he was on Italian soil. Furthermore, he pointed out inconsistencies between American and Italian law regarding criminal insanity as grounds for non-extradition; while American law considers such condition at both time of crime and trial, Italian law only considers it at time of crime - potentially leading to unfair treatment if extradited.