A lawyer for Demps, however, has asked a Gainesville trial judge to reconsider his rejection of Demps' appeal.
And if Judge Robert Cates again turns down Demps appeal, the condemned killer is likely to appeal that decision to Florida's high court.
Demps, 49, is scheduled to die by lethal injection at 6 p.m. May 31.
He was first sent to death row for two 1971 murders in Winter Garden.
But those death sentences were reduce to life prison terms when the U.S. Supreme court halted capital punishment across the country in 1972 because it was so arbitrary.
Before the end of the year, Florida became the first state in the nation to write a new death penalty law. In 1976, the nation's high court upheld three death penalty statutes. One of them was Florida's.
And a couple months later, prison guards at Florida State Prison found Alfred Sturgis bleeding in his cell. On his way to a hospital, Sturgis told a prison guard that Demps and another inmate held him down while a third stabbed him.
Demps was sentenced to death. The other two were sentenced to life in prison.
In 1981, the Florida Supreme Court upheld Demps' death sentence, rejecting his argument that it couldn't stand because the other two inmates received lesser sentences.
Only Demps had the "loathsome distinction of having been previously convicted of the first-degree murder of two persons and attempted murder of another, escaping the gallows only through the intervention of Furman v. Georgia," the high court wrote in its unsigned decision, citing the 1972 decision that vacated death sentences across the country.
All seven justices - none of whom still sit on the high court - signed the ruling.
Since then, Demps has avoided three scheduled electrocutions.
Demps, a Vietnam veteran, was originally condemned for the murders of R.N. Brinkworth and Celia Puhlick, who were fatally shot in a Lake County citrus grove.
The victims were inspecting some land for sale when they happened upon Demps, who had fled to the grove with a stolen safe. Mrs. Puhlick's husband, Nicholas, was wounded.
Gov. Jeb Bush signed a death warrant for Demps on April 24. His latest appeal is based on a memo by a prison employee written the day after Sturgis' murder.
The memo talks about the attack by a single "assailant" and Demps' Gainesville attorney, Bill Salmon, argued that it could have been used to cast doubt on the prosecution testimony against Demps.
Demps filed a handwritten motion in Florida's high court Tuesday asking for a delay and appointment of attorney. He said his lawyer was only representing him at trial level.
But in an unsigned unanimous order, the Supreme Court rejected that request on the grounds that Salmon was representing Demps.
Salmon didn't return a phone call Tuesday.