A prison in Huntsville Texas executed a Mexican national Wednesday night after the U.S. Supreme Court denied a request for an 11th hour stay.

46 year old Edgar Tamayo was convicted for shooting a police officer in 1994. Tamayo had been arrested on suspicion of robbery, but while in the police car Tamayo pulled out a gun and shot the officer in the back of the head.

According to the Mexican government, Tamayo was never informed of his right to diplomatic assistance.

Tamayo's family in Texas and Mexico were devastated upon hearing that the execution had taken place.

Both the Mexican government and U.S. Secretary of State John Kerry asked state officials to consider halting the execution.

After the execution, the family of the slain police officer told reporters justice had been served.

In 2004, the United Nations' International Court of Justice ordered the U.S. to reconsider convictions of 51 Mexicans, including Tamayo, who'd been sentenced to death wi