Ledell Lee was executed minutes before his death warrant was set to expire late Thursday. It was the first time since 2005 that Arkansas had put an inmate to death.
Three other planned executions were canceled this week because of court decisions. Another inmate scheduled for execution next week has received a stay. And three remaining lethal injections face similar hurdles.
"If I were in the state's shoes, I would be prepared for almost double the level of scrutiny," said Brian Gallini, a law professor at the University of Arkansas in Fayetteville.
At the heart of Arkansas' plans is the sedative midazolam, one of three drugs used in lethal injections. The state is racing to carry out the executions before its supply of midazolam expires at the end of the month.
State officials said Friday that they were prepared to move forward with the remaining executions, starting with a double execution on Monday and a single execution on Thursday.
Gov. Asa Hutchinson's office acknowledged that the original plan confronted tall obstacles.
"He knew there was a chance that not all of them would go through," said J.R. Davis, a spokesman for Hutchinson. "It's not surprising that some of the executions have been stayed, but obviously last night we felt the right decision was handed down."
Lawyers for Marcel Williams and Jack Jones, the two inmates set for execution Monday, have filed several legal challenges in hopes of the stopping the executions. A federal judge on Friday rejected claims that the inmates' poor health could make their lethal injections especially painful. Williams has also filed a challenge that claims his lawyers at trial were ineffectual.
Jeff Rosenzweig, an attorney for Jones, said the inmates' conditions raise the likelihood of complications that were not apparent in Lee's execution. Williams is obese and diabetic. Jones has diabetes, high blood pressure and has had a leg amputated in prison.
Authorities received the go-ahead to execute Lee after the U.S. Supreme Court rejected his last appeals. At least one high court justice expressed reservations about the state's push to execute the inmates before its drug expired.
"In my view, that factor, when considered as a determining factor separating those who live from those who die, is close to random," Justice Stephen Breyer wrote Thursday in a dissent.
The legal fight over the executions also included an effort to prevent the state from using another lethal injection drug that its maker said it was misled into selling the prison system, not knowing it would be used for capital punishment.
Vecuronium bromide halts an inmate's breathing. The state Supreme Court lifted a judge's order preventing its use hours before Lee's execution.
Inmates' attorneys also failed in efforts to block the executions based on concerns about midazolam, which has been used in flawed executions in other states.
There were no apparent signs of complications or suffering during Lee's execution, which lasted 12 minutes. But critics of midazolam say that does little to allay their concerns that the drug may not render inmates fully unconscious before they receive drugs to stop their hearts and lungs.
"I don't know what the state is thinking, but just because this one appears to have gone off without a hitch doesn't meant that there are not problems," said Dale Baich, an assistant federal public defender who witnessed Joseph Rudolph Wood's slow death in a lethal injection that involved midazolam in 2014 in Arizona.
Attorneys for the inmates have complained the schedule is stretching their resources thin as they work against the clock. It's also posing a challenge for the state's attorneys, who have been fighting on multiple fronts. The attorney general's office says 20 to 30 of its attorneys have been handling cases related to the inmates' executions.
"We are working to ensure that those sentences are carried out and that justice is served," Attorney General Leslie Rutledge said.
Gallini said trying to salvage the rest of the execution schedule could invite even more intense legal battles "because what started out as kind of a press release and a decision has ballooned" into trending hashtags and international news coverage.
That extra attention, he said, "has brought some major litigation players to the table."
Associated Press Writer Jill Bleed contributed to this report
Follow Andrew DeMillo on Twitter at www.twitter.com/ademillo .
Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.