VARNER, Ark. (AP) — Arkansas was proceeding with plans to conduct the nation's first double execution in more than 16 years after the U.S. Supreme Court allowed the first to move forward, turning back the inmate's claims that his poor health could cause excruciating pain during the lethal injection.

Justices rejected a stay request from Jack Jones, who was set to die at 7 p.m. Monday. A second inmate, Marcel Williams, was set for execution later Monday though he still has pending legal challenges.

In Jones' case, attorneys said he takes a daily dose of two medications to treat chronic pain, and they worry those drugs could desensitize him to the effects of midazolam, a sedative that is the first drug used in Arkansas' lethal injection protocol. Jones also has diabetes and had a leg amputated in prison.

Williams, set for execution at 8:15 p.m., has appeals pending with the U.S. Supreme Court. Williams' "morbid obesity makes it likely that either the IV line cannot be placed or that it will be placed in error, thus causing substantial damage (like a collapsed lung)," his attorneys wrote in a court filing asking justices to block the execution.

Both men were served last meals on Monday afternoon, Arkansas Department of Correction spokesman Solomon Graves said. Jones had fried chicken, potato logs with tartar sauce, beef jerky bites, three candy bars, a chocolate milkshake and fruit punch. Williams had fried chicken, banana pudding, nachos, two sodas and potato logs with ketchup, Graves said.

They would be the second and third inmates executed by Arkansas this month. A fourth execution is set for Thursday. Arkansas initially wanted to execute eight men before a drug used to sedate the inmates expires Sunday, but four other inmates have won stays.

Before Ledell Lee's execution last Thursday, Arkansas hadn't put an inmate to death since 2005. In several of the 31 states where executions are legal, drug shortages have often forced delays as manufacturers prohibit their use in executions. Arkansas believes that secrecy it grants to suppliers can solve that problem, though it still has difficulty obtaining the drugs. Courts have also forced rewrites of Arkansas' lethal injection protocols, causing further delays. Jones and Williams committed their crimes more than two decades ago.

In recent pleadings before state and federal courts, the inmates say the three drugs Arkansas uses to execute prisoners — midazolam, vecuronium bromide and potassium chloride — could be ineffective because of their poor health.

Jones, 52, has lost a leg to diabetes and is on insulin. Williams, 46, weighs 400 pounds, is diabetic and has concerns that the execution team might not be able to find a suitable vein to support an intravenous line.

The poor health of both men, their lawyers claim, could make it difficult for them to respond during a consciousness check following a megadose of midazolam. The state shouldn't risk giving them drugs to stop their lungs and hearts if they aren't unconscious, they have told courts.

In a response filed with the 8th U.S. Circuit Court of Appeals, lawyers for the state said the inmates had filed an "avalanche" of lawsuits to obtain stays. The men's attorneys countered that the state forced their hands.

"If there was an 'avalanche' of litigation, as the state complains, that's because the state created an avalanche of execution dates," Julie Vandiver wrote.

The 8th Circuit rejected Jones' and Williams' requests for stays Monday, and the Arkansas Supreme Court said Monday it wouldn't reopen the men's cases and refused to issue stays. Williams' attorneys once again asked the state Supreme Court to reopen the case in a filing late Monday afternoon, arguing that Williams' prior attorney had plagiarized a court filing years ago.

The initial eight executions would have been the most by a state in such a short period since the U.S. Supreme Court reinstated the death penalty in 1976. The state said the executions needed to be carried out before its supply of the sedative midazolam expires on April 30.

The last state to put more than one inmate to death on the same day was Texas, which executed two killers in August 2000. Oklahoma planned a double execution in 2014 but scrapped plans for the second one after the execution of Clayton Lockett went awry.

Arkansas executed four men in an eight-day period in 1960. The only quicker pace included quadruple executions in 1926 and 1930.

Williams was sent to death row for the 1994 rape and killing of 22-year-old Stacy Errickson, whom he kidnapped from a gas station in central Arkansas.

Authorities said Williams abducted and raped two other women in the days before he was arrested in Errickson's death. Williams admitted responsibility to the state Parole Board last month.

"I wish I could take it back, but I can't," Williams told the board.

Jones was given the death penalty for the 1995 rape and killing of Mary Phillips. He strangled her with the cord to a coffee pot.

In a letter earlier this month, Jones said he was ready to be killed by the state.

"I forgive my executioners; somebody has to do it," wrote Jones, who had a leg amputated in prison because of diabetes and uses a wheelchair.

The letter, which his attorney read aloud at his clemency hearing, went on to say: "I shall not ask to be forgiven, for I haven't the right."

Seven people have been executed in the United States this year, four in Texas and one each in Arkansas, Missouri and Virginia. Last year, 20 people were executed, down from 98 in 1999 and the lowest number since 14 in 1991, according to the Death Penalty Information Center.

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Associated Press writers Jill Bleed contributed to this report from Little Rock.

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