A US court halted Friday what would have been the first federal execution in 17 years, yielding to a request from victims' relatives worried about traveling during the pandemic to watch the inmate die.
Hours later the Justice Department appealed against the decision.
Daniel Lee, a 47-year-old white supremacist, was convicted in 1999 of killing a gun dealer, his wife and her eight-year-old daughter in Arkansas.
Lee had been scheduled to die Monday by lethal injection at a prison in Indiana.
But relatives of the victims, including Earlene Peterson, the grandmother of the little girl, asked this week for the execution to be delayed because of the pandemic.
They said they faced the tough choice of exercising their right to witness the execution and protecting their health by avoiding travel during the coronavirus crisis.
Jane Magnus-Stinson, chief judge of the US District Court for the Southern District of Indiana, agreed to put the execution on hold.
"The public, like the government, has an interest in (the) prompt and orderly execution of Mr. Lee's death sentence," she wrote.
"But the public also has an interest -- codified by Congress -- in ensuring that crime victims are treated with fairness and with respect for the victim's dignity," Magnus-Stinson added.
US prosecutors can appeal the decision all the way to the Supreme Court but Baker Kurrus, a lawyer for Peterson and other relatives of the victims, expressed hope that they would not.
However, the US Justice Department said late Friday that it would in fact appeal to keep the execution on track for Monday.
Peterson opposes the death penalty and has asked the administration of President Donald Trump several times to grant Lee clemency.
The Trump administration has scheduled four executions for this summer, saying it was acting in the interest of crime victims.
Most crimes in America are tried at the state level but the federal government takes up the most serious cases such as terror attacks or racist crimes, among others.
In the last 45 years only three people have been put to death by the federal government, including Timothy McVeigh, who was convicted of bombing a federal government building in 1995, killing 168 people, and executed in 2001.
The last execution at the federal level was in 2003.