HUNTSVILLE, Texas (AP) — Edgar Tamayo, a Mexican national, was executed Wednesday in Huntsville, Texas, for the slaying 20 years ago of a Texas police officer, Guy Gaddis, 24. 

The US Supreme Court had temporarily put on hold the execution of Edgar Tamayo, as justices considered appeals to keep him from the Texas death chamber.

Texas officials have opposed appeals to stop the scheduled lethal injection, despite pleas and diplomatic pressure from the Mexican government and the U.S. State Department.

Tamayo's attorneys and the Mexican government contended Tamayo's case was tainted because he wasn't advised under an international agreement that he could get legal help from his home nation after his arrest.

Legal assistance guaranteed under that treaty could have uncovered evidence to contest the capital murder charge or provide evidence to keep Tamayo off death row, Mexican officials have said.

Records show the consulate became involved or aware of the case just as his trial was to begin.

Secretary of State John Kerry previously asked Texas Attorney General Greg Abbott to delay Tamayo's punishment, saying it "could impact the way American citizens are treated in other countries." The State Department repeated that stance Wednesday.

But Abbott's office and the Harris County district attorney opposed postponing what would be the first execution this year in the nation's most active capital punishment state, where 16 people were put to death in 2013.

Tamayo's lawyers went to the Supreme Court after the 5th U.S. Circuit Court of Appeals said an appeal this week renewing an earlier contention that Tamayo was mentally impaired and ineligible for execution was filed too late.

The Texas Board of Pardons and Paroles on Tuesday rejected Tamayo's request for clemency.

"It doesn't matter where you're from," Perry spokeswoman Lucy Nashed said. "If you commit a despicable crime like this in Texas, you are subject to our state laws, including a fair trial by jury and the ultimate penalty."

Gaddis, who had been on the force for two years, was driving Tamayo and another man from a robbery scene when evidence showed the officer was shot three times in the head and neck with a pistol Tamayo had concealed in his pants. The car crashed, and Tamayo fled on foot but was captured a few blocks away, still in handcuffs, carrying the robbery victim's watch and wearing the victim's necklace.

At least two other inmates in circumstances similar to Tamayo's were executed in Texas in recent years.

The Mexican government said in a statement this week it "strongly opposed" the execution and said failure to review Tamayo's case and reconsider his sentence would be "a clear violation by the United States of its international obligations."

Tamayo was in the U.S. illegally and had a criminal record in California, where he had served time for robbery and was paroled, according to prison records.

"Not one person is claiming the suspect didn't kill Guy Gaddis," Ray Hunt, president of the Houston Police Officers' Union, said. "He had the same rights as you and I would have.

"This has been looked at, heard, examined and it's time for the verdict of the jury to be carried out."

Tamayo was among more than four dozen Mexican nationals awaiting execution in the U.S. when the International Court of Justice in The Hague, Netherlands, ruled in 2004 they hadn't been advised properly of their consular rights. The Supreme Court subsequently said hearings urged by the international court in those inmates' cases could be mandated only if Congress implemented legislation to do so.

"Unfortunately, this legislation has not been adopted," the Mexican foreign ministry acknowledged.

Source: The Associated Press, January 22, 2014