Several hairs found with the victim's body were sent to the FBI in 1984 but could not be tested because the technology was not yet available.

But it is now - and the results could exonerate Wayne Tompkins in the death of Lisa DeCarr, attorney Todd Scher wrote in his Friday letter to Bush.

"Mr. Tompkins maintained and continues to maintain his innocence in the death of Lisa DeCarr," Scher wrote.

But Bush spokeswoman Katie Baur said the execution would not be stayed.

"We're currently investigating the statements made by Mr. Tompkins' lawyer in his letter to the governor and if there is any relevant DNA evidence, we'll take steps to make sure it is properly tested," Baur said.

The issue of DNA testing of death row inmates has gained prominence in Florida since last December when DNA tests came back showing condemned killer Frank Lee Smith was innocent of the murder that landed him on death row for 14 years.

Those results came several months after Smith died on death row of cancer.

Proposals to guarantee access to DNA testing for death row inmates are pending in the Legislature and before the Florida Supreme Court.

In January, Bush wrote state Sen. J. Alex Villalobos in support of the DNA legislation, pointing to the Smith case.

"In some case, DNA testing may provide strong evidence of innocence or guilt," Bush wrote in that letter. "Justice requires that such highly probative evidence be considered when it is available and dispositive of the case."

Tompkins, 44, is set to die by lethal injection at 6 p.m. May 1 for the murder of DeCarr, who disappeared from her Tampa home.

Her remains were found in a shallow grave under her home more than a year later. Tompkins was her mother's boyfriend.

Martin McClain, an attorney consulting on Tompkins case, said that if the hair comes back and matches neither DeCarr's DNA nor Tompkins' DNA, that will raise serious problems with the conviction against Tompkins.

"It's not like it's either a nail in his coffin or the key to setting him free if it's (from) Lisa DeCarr," McClain said.