The man who shot and killed a Dallas officer in 2007 was executed on Wednesday.

On Wednesday, a man convicted of killing a Dallas police officer almost 16 years ago was executed after a high-speed chase.

Wesley Ruiz, 43, was given a lethal injection at a state prison in Huntsville, Texas, for the March 2007 murder of Dallas Police Chief Corporal Mark Nix.

Ruiz led the chase at high speed after being spotted driving a car that matched the description of the car used by the murder suspect. Authorities said Ruiz shot Nix once when an officer attempted to smash the car’s passenger window after a chase. The bullet hit Nix’s badge, shattered it, and sent the pieces down his neck, severing an artery. He later died in the hospital.

Nicks, 33, a veteran of the US Navy’s Operation Desert Storm, had been in Dallas for nearly seven years and was engaged when he was killed.

Earlier Wednesday, the U.S. Supreme Court rejected an appeal by Ruiz’s lawyers seeking a stay of execution. The defense argued that jurors relied on “blatantly racist” and “blatantly anti-Spanish stereotypes” when assessing whether Ruiz posed a future danger, an element necessary for a death sentence in Texas. Ruiz was Spanish.

In court papers filed late Tuesday with the Supreme Court, the Texas Attorney General’s Office said Ruiz’s allegation of juror bias was without merit because a review of the allegations by Dallas County District Attorney John Croizo last week found no such bias. One juror, accused of bias by Ruiz’s lawyers, told Creso that “I have not been and am not biased against anyone or any race,” according to court documents.

Last week, U.S. District Judge David Godbey in Dallas denied Ruiz’s request to stay Ruiz’s execution, saying his lawyers failed to prove that jurors made statements during his trial that showed “clear racial bias.” On Monday, the Texas Court of Criminal Appeals also denied a similar request for a stay on charges of racial bias. The Court of Appeal did not consider the claim on the merits, but dismissed it on procedural grounds.

Ruiz’s lawyers had previously argued, unsuccessfully, that an expert witness for the prosecution had falsely testified at his 2008 trial that Ruiz was a constant threat. His lawyers argued that prosecutors were aware of the false testimony but remained silent. In his ruling, Godbey said the expert’s testimony was “quite possibly harmless” and even if corrected, it would not change the jury’s decision to sentence Ruiz to death.

Ruiz was one of five Texas death row inmates who sued to stop the state’s prison system from using expired and unsafe drugs for execution. Despite an Austin civil court judge tentatively agreeing to the lawsuits, two of the state’s highest courts allowed the execution of one of the inmates involved in the trial on January 10.

The Texas Board of Pardons and Parole on Monday unanimously refused to commute Ruiz’s death sentence to a lighter sentence.

Prison officials reject the lawsuit’s claims and say the government’s supply of execution drugs is safe.

At his trial, Ruiz testified that he feared for his life when, in self-defense, he shot Nicks after an officer allegedly threatened to kill him. He also said that he believed the police were the first to open fire with their weapons.

“I didn’t try to kill the officer. I was just trying to stop him,” Ruiz said.

Ruiz also said that he fled the police that day because he had illegal drugs in his car and took drugs.

Gabriel Luchiano, who knew Nix when he was a security guard, said the officer was always quick to respond when people needed help at the northwest Dallas store where Luchiano worked.

He was a “guardian angel,” Luchiano said. “It still hurts no matter what. Nothing will close it.”

Ruiz became the second prisoner to be executed this year in Texas and the fourth in the United States. Seven other executions are scheduled in Texas later this year, including one next week.