Texas executed Edgar Tamayo Arias, an intellectually disabled Mexican citizen, Wednesday night, despite protests that the act was a violation of both U.S. and international law.

Secretary of State John Kerry even wrote a letter to Republican Texas Governor warning that the execution could hurt diplomatic ties between Mexico and the United States in addition to changing the way American citizens are treated in other countries.

International pressure in the days leading up to the execution proved insufficient to prevent it from going forward. Mexico's foreign minister and ambassador to the United States requested a stay of execution and asked Texas to defer to the judgment of the International Court of Justice. The International Commission against the Death Penalty also urged Texas authorities not to proceed with Tamayo's execution.

Officers purportedly never informed Tamayo of his right to request consular assistance from Mexico when he was arrested in 1994 for the murder of a police officer.

According Diann Rust-Tierney, who is a member of the National Coalition to Abolish the Death Penalty, "The United States and Texas are bound by the Vienna Convention. The Vienna Convention requires all countries who signed it to provide foreign nationals accused of a crime with notice and an opportunity to seek assistance from their consulate."

Another problem with Tamayo's execution is that the U.S. Supreme Court has a precedent prohibiting execution of the mentally disabled. Tamayo's IQ score of 67 is below normal and could be outlawed based on the eighth amendment against cruel and unusual punishment.  

Mexico has said that if the consulate had been informed of the execution charges against Tamayo it could have raised a defense which could have saved his life. As it stood, Tamayo's lawyers never made the argument of the eighth amendment at trial. The amount of international fallout remains to be seen.