Terre Haute, Ind. — A Kansas man who raped and killed a 16-year-old girl and fatally beat an 80-year-old woman is scheduled to be among the first three inmates executed when the federal government resumes the practice after 17 years.

Wesley Ira Purkey, 68, of Lansing, Kansas, is set to die by lethal injection on Wednesday at the U.S. Penitentiary in Terre Haute, Indiana. Those who attend the execution will be required to wear face masks.

Critics have said the decision to resume executions during a pandemic is political and that the death sentences do not need to be urgently fulfilled. But Attorney General William Barr says the government has an obligation to carry out the sentences imposed by courts.

Purkey's execution is expected to be the nation's second this week. Daniel Lewis Lee, 47, of Yukon, Oklahoma was put to death on Tuesday for murdering an Arkansas family in a 1990s plot to build a whites-only nation in the Pacific Northwest.

Defense attorneys argued Purkey is not mentally competent to be executed and that it's not safe to conduct executions during a pandemic.

“He has longstanding issues of mental illness, now suffers from Alzheimer's disease and his dementia has progressed to the point that he no longer has a rational understanding of why the government seeks to execute him,” said one of his attorneys, Rebecca Woodman.

Purkey believes his execution is part of a conspiracy against him by the federal government in retaliation for his frequent complaints about prison conditions, his attorneys said. They argued that the Constitution prohibits putting to death someone who lacks a reasonable understanding of why he is being executed.

Purkey was sentenced to death for the 1998 killing of 16-year-old Jennifer Long in Kansas City, Missouri. He repeatedly stabbed her, cut her body into pieces with a chainsaw, burned her remains then dumped her ashes 200 miles (320 kilometers) away in a septic pond in Clearwater, Kansas.

Nine months later, Purkey was arrested in the killing of 80-year-old Mary Ruth Bales, of Kansas City, Kansas. He was working for a plumbing company when he went to her home in October 1998 to fix a kitchen faucet.

Purkey was sentenced to life in prison after pleading guilty to Bale’s murder.

A federal jury in the Western District of Missouri convicted Purkey in 2003 of kidnapping Long, resulting in her death. He was then sentenced to death.

Woodman argued Purkey has an “excruciating history of trauma at home and school” and that his trial lawyer failed to investigate and present mitigating evidence of his traumatic childhood, which included sexual abuse by a Catholic priest.

Purkey had been set to be put to death in December, before a federal judge put the execution on hold.

On Friday, three mental health organizations urged Barr to stop the execution and commute his sentence to life imprisonment without possibility of parole. The letter — signed by the National Alliance on Mental Illness, Mental Health America and the Treatment Advocacy Center — cites Purkey's childhood history of physical and sexual abuse and his psychiatric problems.

Long’s mother, Glenda Lamont, told the Kansas City Star last year that she planned to attend the execution. The Associated Press has been unable to contact her since the execution has been rescheduled.

“I don’t want to say that I’m happy,” Lamont said last year. “At the same time, he is a crazy mad man that doesn’t deserve, in my opinion, to be breathing anymore.”

Bureau of Prisons officials said they will be able to conduct the executions safely and have held practice drills. Prison officials will check temperatures. The agency will also make personal protective equipment, including masks, gloves, gowns and face shields, available for witnesses, but there are no plans to test anyone attending the executions for COVID-19, officials said.