Convicted killer Daniel Lewis Lee was executed Tuesday morning, marking the first federal execution in 17 years. Overnight, the Supreme Court ruled to move forward with the death penalty.

Daniel Lewis Lee, Death PenaltyScott Olson / Getty Images

Lee's final words were, "I didn't do it. I've made a lot of mistakes in my life but I'm not a murderer. You're killing an innocent man," according to CNN. He was found guilty of murdering a family of three.

The one-time white supremacist was scheduled to die Monday, but a federal judge blocked the planned execution, citing challenges to the federal government's lethal injection protocol.

"It is shameful that the government saw fit to carry out this execution when counsel for Danny Lee could not be present with him, and when the judges in his case and even the family of his victims urged against it," Lee's attorney, Ruth Friedman, said in a statement. "And it is beyond shameful that the government, in the end, carried out this execution in haste, in the middle of the night, while the country was sleeping. We hope that upon awakening, the country will be as outraged as we are."

Earlene Peterson, a relative of the family who were tortured and killed, tells CNN she did not want the death penalty for Lee.  

"The American people have made the considered choice to permit capital punishment for the most egregious federal crimes, and justice was done today in implementing the sentence for Lee's horrific offenses," Attorney General William Barr said in a statement.

In 2019, Barr began working to reinstate the death penalty on a federal level.