Sosa v. Alvarez-Machain is a lawsuit against Francisco Sosa for wrongly detaining Dr. Humberto Alvarez-Machain. Mr. Alvarez-Machain charged Sosa and his other captors with violating international norms that prohibit kidnapping, arbitrary arrest, and detention. His claims rested on the Alien Tort Statute (ATS). CCR filed an amicus brief in support of Mr. Alvarez-Machain.

On April 2, 1990, Mr. Alvarez-Machain was kidnapped and forcibly removed from his Guadalajara office by Francisco Sosa and other Mexican citizens acting on behalf of the U.S. Drug Enforcement Agency. He was brought to the U.S. to stand charges for participation in the 1985 torture and murder of DEA Special Agent Enrique Camarena-Salazar and remained in U.S. custody for more than two years. Mr. Alvarez-Machain was eventually acquitted for lack of evidence and released when it was found that his arrest violated the 1979 United States-Mexico Extradition Treaty.

CCR’s amicus brief supports preserving the ATS upon which Alvarez-Machain's argument centers. The Alien Tort Statute allows foreign nationals to sue for human rights abuses in U.S. courts. CCR has made use of the ATS in dozens of human rights cases since 1979. This case is based upon the precedent established by CCR in Filártiga v. Peña-Irala, a suit which allowed Joel and Dolly Filártiga, Paraguayan nationals, to seek justice for the murder and torture of 17-year-old Joelito Filártiga, Dolly's brother and Joel's son. They were eventually awarded $10.4 million.

CCR was joined by the ATCA Defense Project, the American Civil Liberties Union, Earthrights International, the International Labor Rights Fund, and the Center for Justice and Accountability in filing amicus briefs, which totaled twelve in all. International law scholars, U.S. diplomats, survivors of and relatives of victims of human rights abuses, holocaust survivors, religious groups, human rights organizations, and relatives of 9/11 victims were also among those that joined the effort to preserve the ATS.

On December 14, 1992, Judge Edward Rafeedie of the United States District Court in Los Angeles acquitted Alvarez-Machain and awarded him $25,000 in damages. The court found that the government's case had little evidentiary support and was based on "hunches" and "wild speculation." This decision was upheld by the Ninth Circuit Court of Appeals on February 19, 1997.

However, upon appeal to the U.S. Supreme Court, the Court on June 29, 2004 reversed the Circuit Court’s decision and ruled against Alvarez-Machain. The Court claimed the ATS provided insufficient basis for the suit. CCR disagrees with this decision because it would allow only a narrow set of lawsuits to be filed under the ATS, and it greatly diminishes the ability to try international human rights abuses in U.S. courts. This decision might also diminish the ability to hold the U.S. government and corporations responsible for perpetrating human rights violations around the world.