With his appeals exhausted and the Texas Board of Pardons and Paroles refusing a clemency request. Riley was set to die for fatally stabbing a store clerk during a robbery in 1986 in his hometown of Quitman in East Texas.
His lethal injection would be the 15th this year in the nation's most active death penalty state.
Riley had been a frequent customer at the Shop-A-Minit convenience store and when he walked in and asked for ice cream on a Saturday morning, clerk Wynona Lynn Harris told him to help himself. She was busy counting money.
Riley pulled out a 10-inch butcher knife, stabbed her in the back and kept stabbing. After inflicting nearly three dozen wounds, he walked out with about $1,000 in a money bag and a left a trail of bloody footprints leading toward his home a few blocks away.
"He stabbed her with such force he bent the end of the blade and bent the handle on the concrete floor when he was ramming it through her," recalled Marcus Taylor, the former district attorney in Wood County who prosecuted Riley for capital murder. "The crime scene was extremely violent. He severed bones all over her body."
Speaking to The Associated Press from death row, Riley readily acknowledged the slaying and blamed a gambling addiction for repeatedly getting him into trouble.
"Dice," he said. "I've been a gambler all my life. I was weak. Every time I was locked up, it was dice games I lost."
In 2005, Riley was within days of execution when lawyers contending he was mentally disabled and ineligible for capital punishment won a court-ordered reprieve.
"You can't be scared to die," he said. "After so many years here, you should be prepared for it."
Riley was well known to authorities in Quitman, about 75 miles east of Dallas. When charged with Harris' slaying, he was on probation for forgery for writing a bad check. He received a nine-year prison term in 1980 for burglary but was paroled three years later. He had an earlier prison stint for burglary, plus arrests and jail time in Wood County for burglary, public intoxication, assault and theft.
"It was all my doing," he said of the killing. "It was something that shouldn't have happened. I can't get it out of my head."
He turned himself in to the sheriff's office a few hours after the murder after learning authorities were looking for him. He'd been seen outside the store just before the time of the attack by a man who'd made a milk delivery there. He confessed after detectives found his bloodstained coveralls containing money taken from the store in a field near his home.
Riley was convicted and sentenced to death in 1986, but the Texas Court of Criminal Appeals in 1991 overturned the conviction, finding a potential juror was dismissed improperly. At his retrial in 1995, he pleaded guilty. At punishment, his lawyers argued for life in prison. Prosecutors sought death and jurors agreed with them.
Taylor said the length of time between the crime and the punishment was frustrating.
"He's been on death row longer than the victim lived on this earth," the now retired prosecutor said.
Riley is among the two dozen longest serving of Texas' 334 condemned prisoners. When he arrived on death row in November 1986, 18 inmates had been executed since the state resumed carrying out capital punishment in 1982. Riley now would be the 438th put to death.
"So many guys went through this before," he said, describing himself as lucky and blessed. "I've made peace with God. I've asked him to forgive me. One day that passes just makes it closer. I won't jump up and down, but I'll be free."
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