Roberto Moreno Ramos, the Mexican citizen convicted for murdering his wife and two children with a sledgehammer, was executed by the state of Texas on Wednesday.

Ramos, 64, received a lethal injection after the Supreme Court refused to issue a stay order on his scheduled execution. Although the execution was originally scheduled for 6 p.m. CST (7:00 p.m. EST) it was delayed due to pending decision on appeals. Finally at 9:36 p.m. CST (10:36 p.m. EST) Ramos was pronounced dead, a few seconds after the lethal dosage was administered, Charlotte Observer reported. 

When the warden asked him if he had any last statement, he said he was grateful of "the humane treatment I got in prison in Texas” and also thanked the Mexican consulate for assisting with appeals in his case.

"I'm getting my gold watch that it took the governor 30 years to forge," he said. "Thank you God. Lord, send me a chariot. I'm ready."

Ramos was convicted of killing his 42-year-old wife Leticia, 7-year-old daughter Abigail, and 3-year-old son Jonathan at their home in Progreso, along the Mexico border, in 1992.

Detectives at the time said he bludgeoned his entire family to death and buried all their bodies beneath the bathroom floor of his house because he wanted to marry the woman he was romantically involved with, local news outlet WTOP reported. 

Just days before Ramos was scheduled to be executed, the Mexican government called Texas’ decision "a flagrant violation of human rights and international law,” claiming the convict was never informed he had access to legal aid from the Mexican consulate, which was a right guaranteed by the 1963 Geneva Convention.

In addition, the United Nations International Court of Justice had opposed Ramos’ execution order in 2004, stating the United States had violated the terms of the Vienna Convention on Consular Relations.

“Any death sentence carried out in contravention of a Government’s international obligations amounts to an arbitrary execution,” the experts warned at the time. “We call for his death sentence to be annulled and for Mr. Ramos Moreno to be re-tried in compliance with due process and international fair trial standards.”

The Inter-American Commission on Human Rights echoed U.N.’s opinion, calling on Texas to “fully respect its international human rights obligations.”

However, both Texas Court of Criminal Appeals and the 5th U.S. Circuit Court of Appeals denied a commutation of the sentence or a six-month reprieve in Ramos’ case claiming his lawyer had failed to present enough evidence in front of the court to prove his supposed mental illness and childhood abuse.

While trying to get his client a stay order on the execution, Ramos’s appellate attorney, Danalynn Recer, had issues with controlling his emotions and impulses, because he suffered from bipolar disorder, which played a significant role in the crime he was convicted of. He also said Ramos was beaten during his childhood by his father, which shaped his behavioral traits.

“No fact-finder or decision-maker entrusted with Mr. Moreno Ramos’s life has ever been provided with evidence of [his] ‘diverse human frailties’ to assist them in dispensing the most severe punishment under law,” Recer told the court, Newsweek reported. 

Ramos was the 21st prisoner to be executed in the U.S. this year and the 11th to die by lethal injection in Texas.