Derrick Jackson, 42, would be the 15th Texas prisoner put to death this year in Huntsville in the nation's most active death penalty state. The execution is scheduled for after 6 p.m.
A Harris County jury convicted Jackson and sentenced him to die in 1998 for the September 1988 murders of Forrest Henderson and Richard Wrotenbery, both 31 and chorus members at the Houston Grand Opera.
The Texas Court of Criminal Appeals Monday rejected an appeal from Jackson's lawyers. They had argued prosecutors improperly withheld some evidence from Jackson's trial attorneys and raised questions about whether Jackson could be mentally impaired and therefore ineligible for execution.
Jackson was arrested in 1992 for three robberies and took a plea bargain that put him in prison for 12 years. He was in prison on those convictions when authorities began looking at him as a suspect in the 1988 slayings.
"I made some bad decisions," Jackson told The Associated Press recently from a tiny visiting cage outside death row.
He acknowledged burglaries and robberies but denied involvement in the singers' slayings, blaming his indictment on "aggressive interrogation" by police eager to solve a nearly decade-old double homicide case.
"You know where you were 10 years ago?" he asked. "It's impossible unless you have records. I didn't do it."
He said when detectives asked him about the killings and requested DNA samples from him, he agreed.
"'Y'all can have whatever you want,'" he said he told them. "I want to clear my name."
Houston police detectives working cold cases and using new computer technology were drawn to Jackson in 1995 when a bloody print from a door knob at the murder scene was matched to him. Subsequent DNA testing also pointed to Jackson, confirming the fingerprint evidence.
"If I was in the system with a fair trial, I'd feel a little better," Jackson said from death row.
Bill Hawkins, a Harris County district attorney who prosecuted Jackson, said technology caught up with him.
"The scientific evidence was extremely strong," Hawkins said. "And subsequent defense testing of DNA had his numbers."
Jackson insisted the scientific evidence was manufactured and shaky.
The day of the slayings, Sept. 10, 1988, Wrotenbery and Henderson, both tenors, had been rehearsing for an opera production of Bizet's Carmen.
Wrotenbery, who also was an elementary school music teacher in the Houston suburb of Deer Park, went to Henderson's apartment where he'd been staying following a divorce until he could find a place of his own. Police determined Henderson, who recently returned to Houston after performing with the opera company in Scotland, went to some bars in the city's Montrose area, may have met Jackson there and took him home.
Evidence showed Henderson was stabbed in the chest. Wrotenbery's throat was slashed. Both were bludgeoned with a heavy metal bar that could have been part of a weight set. Wrotenbery may have been asleep when he was killed.
"Killing two guys like that and nothing happened to me? It just don't add up," Jackson said from prison.
The men's wallets were taken along with Henderson's car. A Houston traffic officer tried to pull over the car for speeding but the driver fled, leading police on a chase until the car crashed. The driver managed to run off and escape.
An administrator from the school district where Wrotenbery taught called the apartment manager when the teacher didn't show up for work. The manager found the bodies.
"I remember the deaths were extremely brutal," Hawkins said. "I don't recall handling a case where the scene had as much blood as was there."
Jackson, who was among at least four condemned killers with execution dates in Texas in the coming months, said growing up on Houston's south side put him in the middle of a "crime culture" where many of his friends stole cars and committed burglaries.
"That's what you do," he said. "I could have been a dead a long time ago breaking into people's houses. I count waking up as a blessing. I know a lot of people don't."
Derrick Jackson executed for deaths
"It's not scary, as in fear," Jackson told The Associated Press in a recent interview from death row. "It's more a reluctance that it had to come to this. I don't want to die. but it's not like I'm scared to die.
"It's like you have terminal disease for a number of years and finally they say you're not going to be able to live with it any longer so you're going to have to get your affairs together with your family and within yourself."
Derrick Jackson, who was pronounced dead at 6:20pm local time (2320 GMT), was the 15th person to be executed in Texas this year, officials with the Texas Department of Criminal Justice said.
Jackson, 42, was convicted of the murder of two men whose apartment he entered in September 1988.
He beat and stabbed both men to death before stealing a car that belonged to one of them. After a high-speed chase by Houston police, Jackson managed to evade capture.
He was later arrested and imprisoned after being convicted on involvement in a separate robbery.
While in prison, police re-examined the murder of the two men, and after matching his DNA to genetic material found at the crime scene, Jackson was rearrested, convicted and sentenced to death.
He gave no final statement at his execution, which was attended by his father and two brothers, as well as the father and cousin of one of his victims.
The execution was the 32nd in the United States in 2010. Another three executions are scheduled for later this year in Texas, where 322 people are currently on death row.