Ker v. Illinois, decided in 1886,[2] was the first case to consider whether authorities are allowed to abduct criminal suspects in other countries in order to face trial in the United States.

It held that the Federal Kidnaping Act had changed the rule that a state could constitutionally try and convict a defendant who had been forcibly brought to its jurisdiction.

The Federal Kidnapping Act, was enacted in 1932 and made it a felony to transport any person across state lines.

On substantive grounds, it has been consistently used in support of a general proposition that an illegal arrest does not void a subsequent conviction.

That case involved the abduction of a Mexican citizen by US officials and a violation of the territorial integrity of Mexico country.

The court acknowledged the validity of the Ker-Frisbie doctrine and considered whether it would apply when the illegal abduction was done in the context of violating the clear terms of an extradition treaty.

Justice Stevens wrote the minority opinion, joined by justices Harry Blackmun and Sandra Day O'Connor, writing: “It is clear that Mexico's demand must be honored if this official abduction violated the 1978 Extradition Treaty between the United States and Mexico.”