A Texas man was put to death for setting fire to Nancy Harris, a 76-year-old store clerk, during a robbery in 2012.

HOUSTON, Texas — A man from Texas was executed on Tuesday evening, exactly 13 years after a convenience store robbery during which he set a clerk on fire in a Dallas suburb.

Matthew Lee Johnson, aged 49, was given a lethal injection at the Huntsville state penitentiary. He was sentenced for the brutal attack on 76-year-old Nancy Harris on May 20, 2012, a great-grandmother whom he doused with lighter fluid and set alight in the suburb of Garland. She suffered severe burns and passed away a few days later.

Asked by the warden if he had a final statement, Johnson turned his head and looked at his victim’s relatives, watching through a window close by.

“As I look at each one of you, I can see her on that day,” he expressed, speaking slowly and clearly. “I request your forgiveness. It was never my intention to harm her.” He also said, “I hope that she is the first person I encounter when I pass on and that I will spend eternity with her.”

“I made wrong choices, I’ve made wrong decisions, and now I pay the consequences,” said Johnson, who also asked forgiveness from his wife and daughters.

There was little reaction from Harris’ relatives – three sons, two daughters-in-law and a granddaughter – who witnessed the execution and declined to speak with reporters afterward.

As the lethal dose of the sedative pentobarbital began taking effect, Johnson gasped several times, then made repeated sounds like snoring. Within a minute, all movement stopped. He was pronounced dead at 6:53 p.m. CDT, 26 minutes after the drugs began flowing into his arms.

Johnson’s execution was the second carried out Tuesday in the United States. Hours earlier in Indiana, Benjamin Ritchie received a lethal injection for the 2000 killing of a police officer.

The day’s executions were part of a group of four scheduled within about a week’s time. On May 15, Glen Rogers was executed in Florida. On Thursday, Oscar Smith is scheduled to receive a lethal injection in Tennessee.

Security video captured part of the attack against Harris who, despite her burns, was able to describe the suspect before she died.

Johnson’s guilt was never in doubt. During his 2013 trial, he admitted to setting Harris on fire and also expressed remorse. “I hurt an innocent woman. I took a human being’s life … It was not my intentions to — to kill her or to hurt her, but I did,” he had said at the time.

Johnson said he had not been aware of what he had done as he had been high after smoking $100 worth of crack. His attorneys told jurors Johnson had a long history of drug addiction and had been sexually abused as a child.

Harris had worked at the convenience store for more than 10 years, living only about a block and a half away, according to testimony from one of her sons. She had four sons, 11 grandchildren and seven great-grandchildren.

Prosecutors said Harris had only been working her Sunday morning shift for a short time when Johnson walked in, poured lighter fluid over her head and demanded money.

After Johnson grabbed the money from the register, he set Harris on fire and calmly walked out of the store, according to court documents. Harris frantically tried to extinguish herself and her clothing, exiting the store and screaming for help before a police officer used a fire extinguisher to douse the flames covering her body. Johnson was arrested about an hour later.

Harris suffered extensive second- and third-degree burns over her head and face, neck, shoulders, upper arms, and leg and was in a great deal of pain in the days before she died, a nurse and doctor testified.

Johnson’s legal team did not pursue any appeals this week with the U.S. Supreme Court, according to David Dow, one of the inmate’s attorneys. Lower appeals courts had previously rejected defense requests to stay the execution, and the Texas Board of Pardons and Paroles on Friday denied Johnson’s request to commute his death sentence to a lesser penalty.

In previous appeals, Johnson’s lawyers had argued his death sentence was unconstitutional because he was improperly determined to be a future danger to society, a legal finding that was needed to sentence him to death. His most recent appeals had argued his execution date had been illegally scheduled.

Johnson was the fourth person put to death this year in Texas, historically the nation’s busiest capital punishment state. Tuesday’s executions in Texas and Indiana brought this year’s total in the U.S. to 18 inmates put to death.