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.

Motion to stay because of drugs

The motion filed in the Court of Criminal Appeals in Texas early Wednesday said Howard's attorneys had filed requests for information about the lethal dose of pentobarbital the Texas Department of Criminal Justice planned to use. They say the department asked for a state attorney general opinion about whether they would have to disclose that information, despite a  years-long practice of disclosing information. 

The Texas attorney general opinion is not expected to be returned until after Wednesday, meaning Howard can't litigate whatever decision the state might make on releasing that information, they say.

Texas officials did not immediately return a request for comment Wednesday morning.

Executions in the U.S. this year

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.

Tennessee's Republican Gov. Bill Lee has halted the one remaining execution for the rest of the year.