WASHINGTON — A man sentenced to death for the murder of a police officer is scheduled to be executed Wednesday night in Texas despite suspicions of racism having tainted his trial.

Unless the US Supreme Court grants Wesley Ruiz a last-minute reprieve, the 43-year-old Death Row inmate will receive a lethal injection at the penitentiary in Huntsville, Texas.

Police officers chased Ruiz through the streets of the central Texas city of Dallas in 2007, believing his vehicle was involved in a homicide.

At the end of the chase, Ruiz fired a shot at a police officer who was trying to break the window of his car with his baton. The shot killed the officer.

During his trial, Ruiz asserted that he feared for his life and fired in “self-defense,” local media reported. Nonetheless, jurors sentenced him to death.

In the years that followed, his lawyers launched several unsuccessful appeals.

As the execution date approached, lawyers argued in an emergency motion that jurors relied on “overtly racist” evidence and “blatantly anti-Hispanic stereotypes” in appraising Ruiz’s dangerousness.

One juror had described him as “an animal,” “a mad dog” and considered Hispanics at the trial to be “gang members,” they argued in court papers.

Their case was dismissed at trial and on appeal and is now before the US Supreme Court.

Ruiz has also joined a lawsuit brought by several death row inmates in Texas, who accuse the state Department of Criminal Justice of extending the expiration dates of lethal substances used for executions.

The use of old drugs, they say, risks causing unlawful suffering, since the US Constitution prohibits cruel and unusual punishment.

The authorities assure that their stocks of pentobarbital do not pose a problem.

If the high court does not stay the execution, Ruiz will be the fourth convict to be executed this year in the United States.