Tennessee carried out its first execution in nearly a decade on Thursday evening. Governor Bill Haslam allowed the lethal injection to proceed at a maximum-security Nashville prison, despite controversy over the drug cocktail used and past pleas from the state's three Catholic bishops, who argued that the death penalty was contrary to human dignity and respect for life.

Billy Ray Irick, 59, was pronounced dead at 7:48 p.m. Aug. 9 after an execution that took about 20 minutes. Irick was sentenced to death in 1986 for the rape and murder of 7-year-old Paula Kay Dyer, whom he had been babysitting. Irick confessed to her murder and was found guilty after a six-day trial.

After initially declining to say any last words, Irick then apologized for his crimes, saying, "I just want to say I'm really sorry and that, that's it." His lawyer stated his last meal was a burger, onion rings, and a soft drink, and that he was able to meet with prison chaplains before his execution.

In July, Bishop Mark Spalding of Nashville, Bishop Richard Stika of Knoxville, and Bishop Martin Holley of Memphis wrote a letter to Gov. Haslam asking for him to put an end to the death penalty in the state. The bishops urged him "to use your authority as governor to put an end to the fast-track executions planned for later this year," saying that "the death penalty contributes to the growing disrespect for human life."

"It is within your power to establish your legacy as a governor of Tennessee who did not preside over an execution on your watch," the bishops wrote.

Pope Francis revised the Catechism of the Catholic Church last week to say that the death penalty was now "inadmissible" and an "attack on the inviolability and dignity of the person" due in part to various improvements in modern prison systems and their ability to keep the public safe.

Irick's supporters argued that his execution should be stayed due to his past mental health issues, and concerns over the drugs used in lethal injections. The U.S. Supreme Court declined to block the execution on these grounds in a decision by Justice Elena Kagan.

Justice Sonia Sotomayor dissented from Kagan's decision, saying that she was concerned the method of execution could cause Irick to experience severe pain, and that this could constitute "cruel and unusual punishment."

Going forward with the execution, Sotomayor said, would mean the United States has "stopped being a civilized nation and accepted barbarism."

Significant concerns had been expressed about the drugs to be used in the execution, particularly midazolam, a sedative. Lawyers have argued that the drug does not effectively render the inmate unconscious, and that they are able to feel the effects of the other two drugs in the cocktail.

The drugs previously administered in lethal injections have become increasingly hard for states to acquire, as companies have either stopped producing the drug or refused to sell them for use in executions.

Tennessee currently has 60 inmates on death row. The last execution carried out in the state was in 2009, when Cecil Johnson Jr. was executed for the murder of three people in 1980. Including Irick, seven people have been executed in Tennessee since the year 2000.