The US government carried out its first execution in 17 years on Tuesday, putting to death convicted murderer Daniel Lewis Lee, a white supremacist who tortured a family of Jewish descent to death. In 1996, Lee, 47, and accomplice Chevie Kehoe were convicted for the murders of William Frederick Mueller, his wife Nancy Ann Mueller and his 8-year-old stepdaughter, Sarah Elizabeth Powell, who lived in Searcy County, Arkansas. While Lee was handed the death penalty, Kehoe was sentenced to life imprisonment. Lee's execution by lethal injection had been due to take place in Indiana at 4 p.m. local time on Monday, July 13, but was stayed after a last minute ruling by a US District Court in Washington. Issuing her injunction, Judge Tanya Chutkan had said Lee and other condemned men were likely to succeed in their legal challenge arguing that the single drug used in the lethal injection, the barbiturate pentobarbital, would cause an unconstitutional degree of pain and suffering.However, the Supreme Court disagreed, ruling that the four death row inmates bringing the case, including Lee, "have not established that they are likely to succeed" in their legal challenge, in part because barbiturate pentobarbital has become a "mainstay of state executions."At 2:10 a.m. the Supreme Justices voted 5-4 to clear the way for federal executions to resume, ruling that Lee and other condemned men's challenges to the execution protocol did not justify "last-minute" intervention by federal courts. "Last-minute stays like that issued this morning should be the extreme exception, not the norm," the Supreme Court wrote in its ruling.Lee was pronounced dead at 8:07 a.m. EDT (1207 GMT), US Bureau of Prisons spokeswoman Kristie Breshears said by phone.Asked if he had any last words, Lee is reported to have said "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."Lee was found guilty of a number of offenses, including three counts of murder in aid of racketeering, on May 4, 1999. The court heard how Lee and Kehoe tortured the family, including Sarah, to get them to reveal the location of gold and other valuables, before being suffocated and thrown into the Illinois bayou. Their bodies were found five months after their deaths. Both Lee and Kehoe admitted to being part of a white supremacist group; Kehoe was reportedly raised within the Christian Identity movement, which holds that Jews are the children of Satan, and that whites are the true Israelites, and was known to frequent Elohim City, an Ayrian Nation separatist compound in Oklahoma, where he met Lee. The year before the murders, Kehoe had burgled the Mueller home, stealing a large cache of guns and ammunition from William, a gun-dealer, in addition to cash. That same year, he and another man had also robbed and kidnapped a couple, Malcolm and Jill Friedman, breaking into their home and stealing $16,000. The couple, who were Episcopalians, were told by Kehoe that they were targeted because their surname sounded Jewish, according to the New York Times. According to the Southern Poverty Law Center, Kehoe founded the Aryan Peoples Republic with the plan to cause anarchy through burglary and murder which would eventually lead to the establishment of America as a white-only country, a plan which he involved Lee in, leading to the Muellers' murder.Commenting on the case, Attorney General William Barr said Lee "finally faced the justice he deserved," according to CNN. "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," Barr said in a statement.The US government voted in 1988 to allow the death penalty at a federal level, but since then it has only been used as a sentence in 78 cases, of which just three have been executed. 62 inmates are currently on federal death row. In 2019, Barr reinstated the use of the federal death penalty following a nearly two decade hiatus in its use, instructing the Bureau of Prisons to move forward with executing some "death-row inmates convicted of murdering, and in some cases torturing and raping, the most vulnerable in our society — children and the elderly.""Under administrations of both parties, the Department of Justice has sought the death penalty against the worst criminals," he added at the time. "The Justice Department upholds the rule of law - and we owe it to the victims and their families to carry forward the sentence imposed by our justice system."Lee's execution was opposed by Earlene Peterson, 81, mother to victim Nancy Ann Mueller, however. The family had applied to have the execution delayed so that they could be present to register their dissent, citing coronavirus concerns at the current time, but were ruled against. "Yes, Daniel Lee damaged my life, but I can't believe taking his life is going to change any of that," Peterson said in a video last year. Reuters contributed to this report.