By Brendan O'Brien
(Reuters) - A Texas man who stabbed another man to death for failing to pay back a $100 debt to an exotic dancer was executed on Thursday by lethal injection, a state corrections official said.
Arturo Diaz was pronounced dead at 6:30 p.m. CT (2330 GMT) in Huntsville, according to Jason Clark, spokesman for the Texas Department of Criminal Justice. It was the 13th execution this year in Texas and the 27th in the United States.
"Let's go warden. I'm ready," were his last words, Clark said.
Diaz, 37, was convicted of killing Michael Ryan Nichols in April 1999 in McAllen, near the Mexican border, after the two spent a night partying with an exotic dancer and friends, according to an account of the incident by the Texas Attorney General's Office.
During the course of the evening, Nichols borrowed $100 from the dancer, who returned the following night to collect her money, the account said.
When Nichols gave her only $50, Diaz arrived with an accomplice, Joe Cordova, who held Nichols while Diaz stabbed him, the account said.
A witness who helped the two men throw away a trash bag that contained Nichols' bloody clothes said he heard them talking about a murder Diaz had committed with Cordova's help.
A psychologist testified during Diaz's trial that Diaz had suffered head trauma as a result of being knocked unconscious during fights and having been in a car accident, all of which could "impair his ability to control and regulate his judgment and perceive reality," according to the official account.
The psychologist also testified that Diaz has a low-average intelligence, the verbal ability of an 11-year-old, and a history of antisocial behavior as a child, according to the account.
Diaz was sentenced to death, and Cordova to life in prison, according to the Texas Department of Criminal Justice website.
Diaz was executed using the drug pentobarbital, Clark said. In August, Texas officials said the state's supply of the drug would run out this month.
Asked this week how much pentobarbital the state has on hand, a spokesman would only say that the Texas prison system would be using the drug for the foreseeable future.
"We have not changed our current execution protocol and have no immediate plans to do so," said Clark, who did not explain what had changed since August.
Clark said the dose that would be used in Diaz's execution is not an expired dose.
Texas switched to pentobarbital, a barbiturate that is the drug of choice for physician-assisted suicide in Europe, when the state had to change drugs after the maker of sodium thiopental, Hospira Inc, stopped manufacturing it.
Denmark's Lundbeck LLC, which makes pentobarbital, has objected to its use in executions, leaving it in short supply as well.
Several states have reported running low on pentobarbital and some have halted executions while they seek access or resolve other lethal injection issues, said Richard Dieter, executive director of the Death Penalty Information Center.
(Reporting by Brendan O'Brien; Editing by Cynthia Johnston and Stacey Joyce)