Arkansas executed a death-row inmate late Thursday night in the state’s fourth lethal injection in eight days, concluding a frantic execution schedule officials said was needed to carry out death sentences before one of their deadly drugs expired.

The aggressive timetable drew international scrutiny and criticism, pushing Arkansas into the epicenter of American capital punishment as it attempted to carry out an unprecedented wave of executions. Court orders ultimately blocked half of the scheduled lethal injections, including a second that had also been scheduled for Thursday night, even as the state was able to resume executions for the first time in more than a decade.

The execution of Kenneth Williams, who was convicted of killing a man he fatally shot after escaping from a prison where he was serving a life sentence for another killing, came after his attorneys appealed to the U.S. Supreme Court, arguing that he was intellectually disabled and not fit to be executed. Arkansas officials pushed back, saying these attorneys were only trying to delay his lawful sentence.

Relatives of another of Williams’ victims — a truck driver killed while Williams fled from police following his prison escape — also pleaded for his life, calling on the governor to call off the execution.

These pleas went unanswered, and Williams, 38, was executed late Thursday, according to the Associated Press, which has reporters serve as media witnesses in Arkansas. The lethal injection was pushed further into the night after Williams’ attorneys sought a stay from the U.S. Supreme Court, but the justices shortly after 10 p.m. denied the requests without explanation or any noted dissents.

Williams’ execution ends a tumultuous period in Arkansas, which had long sought to resume executions after last carrying out a death sentence in 2005. Gov. Asa Hutchinson (R) originally set eight executions to occur during an 11-day span, a timetable without equal in the modern history of the death penalty in the United States, sparking concerns about the pace and the possibility of mistakes.

State authorities said this schedule was necessary because one of their lethal injection drugs — midazolam, a common sedative that has been controversial when used in executions — expires at the end of April. Pointing to an ongoing shortage of lethal injection drugs, sparked in part by drug companies’ objections to their products being used to kill people, officials said they had no guarantee of obtaining more drugs and needed to carry out the sentences of eight men convicted of capital murder, some decades ago.

This schedule prompted a flurry of legal challenges, both from the death-row inmates and drug companies. Court orders halted four of the planned executions, including three of the first four scheduled last week, but state officials continued their legal battle in state and federal court for the remaining lethal injections on the calendar.

Before Thursday night, Arkansas carried out three other executions this month. Last week, the state executed its first death-row inmate in 12 years and then, on Monday night, officials put two inmates to death in the country’s first back-to-back lethal injections in nearly two decades. After Williams’ execution, it is unclear when Arkansas will next attempt to carry out sentences for the 29 men remaining on death row.

Williams, the youngest death-row inmate set to die under the schedule Hutchinson approved, was executed at the same inmate he escaped from in 1999. While serving a life sentence for killing Dominique Herd, an 18-year-old cheerleader, he hid in a garbage truck and escaped, according to court records.

Williams arrived at the home of Cecil Boren, who lived near Grady, Ark., not far from the prison, and found the man working on his car. Williams fatally shot him, dragged his body to a bayou and fled with his car, according to court filings, and was only captured after a car chase that killed Michael Greenwood, a truck driver.

Attorneys for Williams said he suffered an intellectual impairment and that he changed in prison, becoming an ordained minister. Relatives of those people whose lives he cut short took sharply different views on whether his execution was warranted.

Genie Boren, who was at church when her husband was killed, lives in the same home where he was attacked, just two miles from the Cummins Unit prison where Arkansas executions take place. Boren said she planned to witness Williams’ execution.

“Years ago, I said I probably would not attend that, because that’s not something that I thought I’d want to see, somebody die,” Boren, 73, said in a recent telephone interview. “My girls and I decided that we should do that, that we should attend.”

Boren said she regularly drives by the prison. “I always look over that way, because I know he’s there,” Boren said. “And once he’s gone, I’ll know he’s gone.”

Relatives of Greenwood, though, pleaded for Williams’ life on Thursday. They asked the governor to stay his execution, saying that they do not want him put to death and do not want more suffering.

Kayla Greenwood, who was 5 when her father was killed, wrote a letter to Hutchinson asking for him to call off the execution. She also reached out to Williams’ relatives after seeing media reports about Williams’ daughter wanting to see him one last time and introduce him to her daughter, Williams’ grandchild.

Greenwood said her family decided to pay for plane tickets so Williams’ daughter, Jasmine, could fly to Arkansas with her 5-year-old daughter from their home near Seattle. Greenwood and her relatives — including her mother, Stacey, and the twin boys she was pregnant with when Michael Greenwood was killed — then drove from their homes in Missouri, picked Jasmine and her daughter up from the airport in Little Rock and drove them to the prison about 77 miles away.

Jasmine asked the Greenwood family to wait outside the prison while she visited her father because prison officials would not allow them to visit Williams, Kayla Greenwood said.

“Watching her leave the prison and knowing that was probably their last goodbye broke my heart,” Greenwood wrote in a letter to Hutchinson on Thursday asking for the execution to be halted. “Jasmine has done nothing at all, but like me, she could lose her father.”

Attorneys for Williams had sought to have his execution delayed, at one point arguing that one of the state’s earlier executions was botched and saying it meant his lethal injection should be postponed. Justice Samuel A. Alito Jr., who is assigned cases from the federal circuit covering Arkansas, referred Williams’ to the full court, which rejected it.

State and federal courts, along with the U.S. Supreme Court, have been repeatedly asked to weigh in on the executions, with inmates filing a volley of stay requests and drug companies unsuccessfully asking judges to keep their drugs from being used.

A federal judge earlier this month blocked one of two executions scheduled for Thursday night, staying it because a state parole board said it would recommend changing that inmate’s sentence to life without parole. The first two executions on the calendar, planned for April 17, were both stayed by the Arkansas Supreme Court; the U.S. Supreme Court rejected a last-ditch appeal from state officials seeking to carry out one of the death sentences. Two more executions were planned for April 20, and while one was blocked by the state Supreme Court, the second that night was carried out, breaking the state’s 12-year execution hiatus.

Arkansas returned to the death chamber earlier this week, executing two inmates on Monday night, a feat unseen since Texas carried out a double execution in 2000. Jack Jones Jr. and Marcel Williams, both convicted of murder, had appealed to the U.S. Supreme Court, but those appeals were rejected. Both men described medical issues that their attorneys argued could complicate their lethal injections.

Jones was sentenced to death for raping and killing a bookkeeper named Mary Phillips and severely beating her daughter during the same incident in 1996. Williams was sentenced to death in 1997 for abducting, robbing, raping and killing Stacy Errickson, who was living at Little Rock Air Force base while her husband served overseas.

Jones was executed first. Williams’ execution, intended to occur not long after, was delayed after his attorneys filed court motions saying that the first lethal injection was botched, prompting a federal judge to briefly stay the second one planned that night.

Williams’ attorneys said corrections officials struggled while inserting an intravenous central line and then did not follow departmental policy in making sure Jones was unconscious five minutes after they began administering midazolam, the sedative used as the first in the state’s three-drug protocol. They also said Jones was “moving his lips and gulping for air.” One media witness said Jones’ lips moved, “but only very briefly at the start of the process,” while another also said his lips moved briefly after the sedative was first administered.

Arkansas state officials pushed back on Williams’ attorneys, arguing that the claims were “inaccurate,” rejecting the description of Jones as gulping for air and moving his lips and saying that “no constitutional violation” occurred during the lethal injection. U.S. District Judge Kristine Baker, who had issued the temporary stay, later lifted her order after a hearing, and Williams was pronounced dead a little more than three hours after Jones. According to internal logs released by Arkansas officials, Jones’ execution took 14 minutes and Williams’s took 17 minutes.