 HOUSTON — Secretary of State John F. Kerry and a former Texas governor are part of an international coalition trying to halt Texas' execution of a Mexican citizen this week. Story highlights Defense attorneys are expected to present oral arguments Tuesday 
 
 Edgar Tamayo Arias is scheduled to be executed in Texas on Wednesday 
 
 Mexico's government says the execution would violate international law 
 
 Tamayo was convicted in the 1994 killing of a Houston police officer 
 
 Mexico's government is trying to block the execution of a convicted cop killer in Texas this week, arguing that it would violate international law. His attorneys are scheduled to present oral arguments Tuesday, calling for a preliminary injunction to stop the state's governor and the Texas Board of Pardons and Paroles from considering Tamayo's clemency petition until the process is "adequate and fair," read a statement from his team. Allowing Mr. Tamayo's fate to be decided by a board that has refused to provide meaningful consideration of evidence that Mr. Tamayo has mental retardation and that his trial was fundamentally unfair as a result of the violation of his consular rights is an affront to what clemency is supposed to be," the attorneys said in a statement. "Mr. Tamayo was never informed of his treaty rights at the time of his arrest, and no court has agreed to review that treaty violation and the consequences that it had for his conviction and sentence," she told CNN affiliate KTRK 
 
 Prosecutors have disputed that argument. The judges ordered the United States to provide "review and reconsideration" of the sentences and convictions of those Mexican prisoners as a result. "Since 1994, this case has gone to all the courts that it can possibly go to -- the state courts, the federal courts," Roe Wilson, assistant district attorney in Harris County, Texas, told KTRK. Mexican officials have petitioned the U.S. on Tamayo's behalf, including Foreign Secretary Jose Antonio Meade and Ambassador to the U.S. Eduardo Medina Mora. Mark White and legal and international organizations have called on the The Texas Board of Pardon and Paroles and Gov. "I have no reason to doubt the facts of Mr. Tamayo's conviction, and as a former prosecutor, I have no sympathy for anyone who would murder a police officer," he wrote in September, adding that he was concerned that Texas' handling of the case could affect the way Americans are treated overseas. "This issue has become and could continue to be a significant irritant in the relations between our two countries," the ambassador wrote. Jason Clark, a spokesman for the Texas Department of Criminal Justice, said they planned to use compounded pentobarbital to execute Tamayo, and declined to comment about other drugs they have.
– Edgar Arias Tamayo is scheduled to be executed in Texas tonight—despite a number of high-level requests that the execution be halted because Tamayo's arrest violated international law. The Mexican citizen was initially arrested after a 1994 robbery; while in the patrol car, Tamayo, now 46, shot the arresting officer in the back of the head, killing him. But authorities never notified Tamayo that he had the right to contact the Mexican Consulate, and that failure violates an international treaty, the New York Times reports. Tamayo's attorney says he was mentally ill, brain-damaged, and developmentally disabled—"just the type of person the protections of the Vienna Convention were designed to help," the Los Angeles Times reports. In 2004, the World Court ordered Tamayo's conviction and 50 others reviewed because of Vienna Convention violations, but Tamayo's never was; Texas says it's not bound by that order. John Kerry, a former governor of Texas, the Mexican government, and a human rights group have all asked Texas Gov. Rick Perry and the state attorney general to stop Tamayo's execution until the case is reviewed, but they appear unswayed. (Kerry expressed a concern that the execution "could impact the way American citizens are treated in other countries," CNN reports.) Tamayo's lawyers unsuccessfully filed for clemency and Tamayo's request for a stay of execution was denied; they're looking into appeal options.