In the end his scheduled death was delayed by only two hours as the high court considered last-minute appeals.
Tamayo was sentenced to death for murdering a Houston cop, Guy Gaddis. The lead-up to his execution led to a tense diplomatic situation, and even Secretary of State John Kerry weighed in, attempting to halt Tamayo's death, reports CNN.
The 46-year-old was killed by lethal injection at 9:32 p.m. Central Time.
Here's what you need to know:
1. He Shot a Cop 3 Times in the Back of the Head
Tamayo was found guilty of shooting a cop, Guy Gaddis, 24, three times in the back of the head. Back in 1994, Tamayo was being brought away from a robbery scene when he shot Gaddis. According to reports, Tamayo had a pistol hidden in his pants at the time he was put in the car. Cops caught up to Tamayo a block away from the shooting, he was apparently wearing Gaddis' watch when police nabbed him. Later, he was found guilty of the murder of Gaddis and sentenced to death.
— The Bishop (@BillBishopKHOU) January 22, 2014
In addition to being a Houston cop, Gaddis was a U.S. Army veteran of Desert Storm. He was survived by his wife and parents.
2. He Died on January 22, 2 Hours After He Was Supposed To
Just minutes before his execution, a last minute ruling from the U.S. Supreme Court halted proceedings. SCOTUS considered appeals to spare Tamayo's life, but around two hours later, SCOTUS cleared the way for the state to execute the man.
Tamayo's lawyers were less concerned about the international implications of their client's execution and were trying to get a stay of execution based on his mental capacity, reports The Associated Press. A Facebook campaign was set up to try to save Tamayo's life.
3. John Kerry Tried to Stop the Execution
Secretary of State John Kerry contacted the Texas Attorney General Greg Abbott to request stay of execution due to Tamayo's Mexican citizenship. The State Department expressed concerns that Tamayo's execution may set a precedent for how Americans are treated abroad. Kerry's statement read:
I want to be clear: 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, This is a process issue I am raising because it could impact the way American citizens are treated in other countries.
The Mexican government said it was "extremely opposed" to Tamayo's execution. It's argued that Tamayo is protected under the Vienna Convention on Consular Relations.
Activists were also arguing that Tamayo was not advised of his right to request help from the Mexican government at the time of his arrest. In 2008, the Mexican government tried, and failed, to halt the execution of Mexican national Jose Ernesto Medellin, who was convicted of raping and killing two teen girls. Again in 2011, the execution of another Mexican citizen in Texas, Humberto Leal Garcia Jr., who was found guilty of murdering a 16-year-old girl in 1994, caused uproar from the Mexican government.
— Amnistía Int. México (@AIMexico) January 22, 2014
The International Court of Justice found, in 2004, that "the United States of America has breached its obligations to Mr. Avena and 50 other Mexican nationals and to Mexico under the Vienna Convention on Consular Relations."
4. Before Murdering Gaddis, Tamayo Had a Rap Sheet
He entered the U.S. illegally sometime in the early 1990s and remained undocumented. Prior to the shooting, Tamayo had arrests for robbery and parole violations.
— Amnistía Int. México (@AIMexico) January 21, 2014
5. Tamayo Is Texas' First Execution in 2014
If the execution of Tamayo goes ahead it will be the state's first of the year. Texas is far and away America's leader in capital punishment, with 16 executions in 2013. The nation's second placed state, Florida, had nine.
Between 1976 and 2006, Texas executed nearly 400 inmates; in the same time period, Virginia, which placed second on the list, executed 98.