DALLAS — A Texas man who fatally shot a convenience store clerk is set to die by lethal injection on Wednesday in what would be the nation’s 30th execution this year.

Jamaal Howard, 46, was found guilty of capital murder in the 2000 killing of Vickie Swartout, 42, who was shot once in the chest. He is set to receive a lethal dose of pentobarbital in the first scheduled execution in the U.S. since Tennessee’s failed attempt at putting Christa Pike to death last week.

Pike’s attorneys said Tuesday that she was awake and speaking as she received treatment at a hospital.

Texas has executed six people so far this year, with two more scheduled after Howard.

Swartout was fatally shot during the robbery at the store in the small, rural town of Silsbee, located about 100 miles (161 kilometers) northeast of Houston. Evidence presented at the trial included the store’s surveillance video, which showed Howard shooting Swartout.

Howard, who was 20 at the time, took $114 and a carton of cigarettes from the store, according to court records.

His attorneys have argued that Howard is intellectually disabled and his execution should be halted. The state said that he has not presented evidence that would show he meets the requirements for a claim of intellectual disability.

He has an appeal to the U.S. Supreme Court pending to stop the execution.

The Supreme Court in 2002 had barred the execution of intellectually disabled people. But it has given states some discretion in how they determine such disabilities.

Florida has carried out 16 executions so far this year, the most of any state. Most states that allow executions use lethal injection as their primary method.