Arkansas on Monday night carried out the first double execution in the U.S. since 2000 despite concerns that the first of the two was inhumane.

Jack Harold Jones, 52, died at 7:20 p.m. CDT, after authorities administered a lethal injection 14 minutes earlier, the Arkansas Department of Correction said. Fellow death-row inmate Marcel Wayne Williams, 46, was pronounced dead just over three hours later, at 10:33 p.m. CDT, according to officials at Cummins Unit prison, about 75 miles southeast of the state capital, Little Rock.

The two prisoners were among eight that the state had planned to execute in 11 days this month, before its supplies of the controversial sedative lethal sedative midazolam expire. However, a court order has placed a stay of execution for four of the inmates.

Jones and Williams were initially scheduled for execution just one hour apart, but lawyers for Williams had appealed for an emergency stay of execution, alleging that Jones lethal injection appeared torturous and inhumane.

U.S. District Judge Kristine Baker issued a temporary stay of Williams execution following the lawyers petition, but lifted the stay less than an hour later.