In Ker v. Illinois, 119 U.S. 436 (1886), a messenger forcibly kidnapped the defendant from Peru and brought him back to the United States, even though he had been sent to Peru with a valid warrant and instructions to obtain the defendant with the cooperation of the local authorities.
Applying its decision in Ker, the Supreme Court upheld the conviction over challenges based on due process and federal kidnapping laws.
More recently, the Supreme Court relied on the Ker–Frisbie doctrine in United States v. Alvarez-Machain, 504 U.S. 655 (1992).
Álvarez Machaín, a Mexican citizen, was abducted and brought to the United States at the direction of the Drug Enforcement Administration.
The Court rejected the argument that such abductions undermine the usefulness of extradition treaties, and it refused to read general principles of international law weighing against such abductions into the Mexican extradition treaty.