TALLAHASSEE, Fla. — Lawyers for Florida serial killer David Gore asked the U.S. Supreme Court on Tuesday to block his planned execution later this week.

The 58-year-old convict is scheduled to receive a lethal injection on Thursday at Florida State Prison in Starke for the 1983 rape-murder of 17-year-old Lynn Elliot in Indian River County. Gore also is serving life terms for killing five other girls or women, who were raped and dismembered.

His attorneys asked for a stay and filed an appeal based on a recent Supreme Court ruling that dealt with ineffective legal assistance.

The nation's highest court ruled last month in an Arizona case that the federal courts must hear a convict's claim of receiving ineffective legal assistance — or none at all — for appeals alleging the inmate's trial lawyers also had been ineffective.

Procedural issues cannot be used to block those appeals, the federal justices ruled in the 7-2 opinion. That decision is limited to states including Florida that do not let defendants claim ineffective counsel until after their initial appeals are resolved.

Gore contends his death sentence should be lifted because a prior appellate lawyer failed to locate a key witness for an appeal that the Florida Supreme Court ultimately denied in 2007. In that appeal, Gore had alleged his trial lawyers were negligent during the case's penalty phase.

The Florida Supreme Court rejected a similar appeal Monday. The unanimous opinion said that while the federal justices' decision contains expansive language, they specifically declined to address the issue of whether there's a constitutional right to effective assistance of counsel in collateral appeals.

Gore's lawyers are asking the U.S. Supreme Court to declare that right in his case.

The state justices also wrote it appears the Arizona decision was directed toward federal rather than state court proceedings "and is intended to address issues that arise in that context."

Gore's appeal also contends his constitutional rights were violated by the governor's "absolute discretion to carry out death sentences based upon subjective whims or outside influences."

Gov. Rick Scott signed Gore's death warrant after his case was brought to the governor's attention during a newspaper editorial board interview.

A final argument is that his due process rights were violated during clemency proceedings because he didn't have an opportunity to be heard or represented by counsel.

Gore and his cousin, Fred Waterfield, picked up Elliott and a 14-year-old friend who had been hitchhiking. Gore threatened the girls with a gun, handcuffed them and took them to his home. Waterfield, who is serving two life sentences, left before Gore raped the girls, according to authorities.

Elliott managed to run from the house, naked and bound. Gore, also naked, ran after her and shot her twice in the head, the authorities said. A boy saw what happened and told his mother, who called police.