Convicted serial killer Tommy Lynn Sells, who was sent to prison in 1999 and claimed responsibility for dozens of murders across the country, was executed Thursday in Texas.
Sells, 49, was convicted of killing 13-year-old Katy Harris while she slept in her Del Rio, Texas, home. Her murder landed Sells on death row, but he has been linked to at least 17 other killings and claims he has killed as dozens more.
Sells declined to make final remarks before his death, then took a few breaths, closed his eyes and began to snore as the lethal-injection drugs took effect, The Associated Press reported. He soon stopped moving and was pronounced dead 13 minutes later at 6:27 p.m. CT.
Sells' execution earlier had been halted when a district court ruled that the Texas prison system was required to disclose information about its lethal-injection drugs supplier and how the drugs are tested. But a federal appeals court on Wednesday threw out the ruling and reversed the decision.
Sells' attorneys made a plea to the U.S. Supreme Court to stay the serial killer's execution, but their plea was rejected Thursday.
In a statement to ABC News Thursday, Sells' attorneys said, "It is our belief that how we choose to execute prisoners reflects on us as a society. Without transparency about lethal injections, particularly the source and purity of drugs to be used, it is impossible to ensure that executions are humane and constitutional. It is our hope that the U.S. Supreme Court and the Texas courts will ultimately agree that we must have transparency about the execution process in order to ensure that prisoners are able to protect their Eighth Amendment rights."
Sells was a subject in a 2010 special ABC News report entitled, "Nightline Prime: Secrets of Your Mind," which followed the inner workings of the human brain and its effects on behavior. He was included in a segment about researchers studying the brain scans of murderers and psychopaths in hopes of discovering why someone would turn into a vicious killer.
Sells, an extreme example of someone with a murderous mind, talked about his gruesome past with ABC News in a chilling 2010 jailhouse interview.
As a young boy growing up in St. Louis, Sells was addicted to killing by the time he was 14.
"I am hatred. When you look at me, you look at hate," Sells said in 2010. "I don't know what love is. Two words I don't like to use is 'love' and 'sorry,' because I'm about hate."
His drifter lifestyle helped him elude police for nearly 15 years as his victims turned up from coast to coast. Sells said his drug use fueled his killing sprees.
"The first time I did a shot of dope, it was the best feeling I ever had in my life. The first time I killed somebody, it was such a rush," Sells told ABC News at the time. "It was just like that, a shot of dope every time I did it, it was that rush again, and I started chasing that high."