A Texas inmate scheduled to be executed this week for killing a female impersonator 15 years ago insists the death was an accident during sex and has made multiple appeals to the U.S. Supreme Court.

Jurors at his trial, though, were convinced that Richard Masterson intentionally strangled 35-year-old Darin Shane Honeycutt, stole his car and fled to Florida before being arrested with another stolen car.

Masterson, 43, is set for lethal injection Wednesday evening for Honeycutt's slaying.

He would be the first person put to death this year in Texas, which carries out more executions than any other state. Its 13 lethal injections last year accounted for almost half of the 28 executions nationwide.

Lawyers for Masterson had multiple appeals pending at the U.S. Supreme Court on Tuesday, after failing in lower Texas and federal courts to block his execution.

Attorneys argued that Honeycutt's death was accidental or the result of a heart attack, that a Harris County medical examiner with questionable credentials was wrong to tell jurors it was a strangulation, that Masterson's earlier lawyers failed to discover the information and that his prolonged drug use and then withdrawal while in jail contributed to his "suicide by confession" when he spoke with police.

His lawyers also contend that the Texas Court of Criminal Appeals denied Masterson his rights to due process and access to the courts by refusing their challenge to a new Texas law that keeps secret the identity of the provider of pentobarbital that Texas prison officials use for lethal injections.

Lawyers for the state argued that Masterson's attorneys offered no scientific evidence about Honeycutt's death that hadn't been previously raised and rejected, including at Masterson's trial. According to court filings, Masterson confessed to police, told a brother he killed Honeycutt and wrote to Texas' then-Attorney General Greg Abbott in 2012 acknowledging the slaying.

"I meant to kill him," Masterson wrote to Abbott, who is now Texas' governor. "It was no accident."

Earlier this month, however, Masterson told the Houston Chronicle from death row that while he accepted responsibility for Honeycutt's death, "I never admitted I murdered anybody."

Masterson had a long drug history and criminal record beginning at age 15. Court documents show he ignored advice from lawyers at his 2002 trial and insisted on testifying.

He told jurors he met Honeycutt, who used the stage name Brandi Houston, at a bar and they went to Honeycutt's Houston apartment, where Masterson said the chokehold was part of an autoerotic sex act.

Honeycutt's body was found Jan. 27, 2001, after friends became worried when he failed to show up for work.

Evidence showed Masterson had taken Honeycutt's car and dumped it in Emerson, Georgia. He was caught more than a week later at a Belleview, Florida, trailer park with another stolen car. The owner of that car testified about meeting Masterson in a Tampa bar frequented by gay men and told of a similar attack where he was choked unconscious by Masterson and robbed.

In his testimony, Masterson told jurors he was a future danger — an element they had to consider when deliberating whether a death sentence was appropriate.

"Everyone has to live and die by their own actions," Masterson said.

Jurors sent him to death row. His case has recently drawn the attention of Pope Francis, who has reinforced the Catholic Church's opposition to capital punishment.