A man who killed a Navy wife after answering her personal ad on Craigslist may end up changing the way death-penalty cases are defended in Florida.

Lawyers for David Kelsey Sparre, 22, are asking the Florida Supreme Court to throw out his death sentence for the murder of 21-year-old Tiara Pool, whose body was found with an estimated 89 slashes inside her Hodges Boulevard apartment in July 2010.

Sparre arranged to meet Pool while her husband, with whom her marriage had become troubled, was deployed at sea. Sparre later told police he killed Pool for the "rush."

In court filings Tallahassee Assistant Public Defender Nada Carey argues that Circuit Judge Elizabeth Senterfitt was wrong to sentence Sparre to death without allowing evidence to be presented on his mental-health and substance-abuse issues.

Sparre told his lawyers he didn't want to mount a defense. But Carey said that when death-penalty defendants refuse to defend themselves, the state still has an obligation to consider factors that would justify life in prison without parole instead of Death Row.

"A sentence of death resulting from anything less than a full airing of the relevant facts in mitigation does not meet the constitutional standards of reliability recognized by this court," Carey said in court filings.

Oral arguments before the Supreme Court are scheduled for Tuesday.

At a death-penalty hearing prior to sentencing, Chief Assistant Public Defender Refik Eler, who defended Sparre at trial, had planned to introduce evidence that he was mentally unbalanced and had been abusing drugs and alcohol since he was 11.

But Sparre instructed Eler not to present any evidence on his behalf. With no defense, and friends and family of Pool testifying for the prosecution during the hearing, the jury that convicted Sparre unanimously recommended he get death and Senterfitt followed its recommendation.

The Supreme Court should send Sparre back for a resentencing and require the appointment of special counsel to present mitigating evidence in cases where a defendant does not contest the death penalty, Carey said.

Assistant Attorney General Charmaine Millsaps argued that the idea of appointing a special counsel every time death-penalty defendants refuse to defend themselves is impractical.

"The source of most mitigation is the defendant himself and he will refuse to assist special counsel," Millsaps said in court filings.

Defendants also have a right to choose their own defense, and appointing special counsel would violate that right, Millsaps said.

The Florida Supreme Court dealt with this issue once before in another Jacksonville murder case.

James William Hamblen killed 34-year-old Laureen Jean Edwards in 1984 when he saw her trigger a silent alarm as he robbed her Beach Boulevard lingerie store. He ordered her back into a dressing room and shot her in the back of the head at close range.

Hamblen confessed at the scene, fired his public defender and represented himself, insisted on pleading guilty and argued that he should be executed.

On appeal, lawyers for Hamblen said the judge shouldn't have allowed him to represent himself during the death-penalty phase because Hamblen wanted to be executed. The Supreme Court rejected that argument, finding that Hamblen had a constitutional right to represent himself.

He was executed in 1990 when he was 61.

Carey argues that the Supreme Court should overturn the Hamblen precedent and create a new one while Millsaps argues that Hamblen is a precedent that should be followed in this case.

Larry Hannan: (904) 359-4470