STARKE, Fla. -- A federal appeals court has blocked the scheduled execution of a mass killer convicted of eight slayings that jolted South Florida in the 1970s.

The 11th U.S. Circuit Court of Appeals granted a last-minute request Tuesday night from attorneys for 64-year-old John Errol Ferguson, who has been on Florida's death row for 34 years.

Ferguson's lawyers contend he should not be executed because he suffers from severe mental illness.

Florida officials immediately asked the U.S. Supreme Court to lift the stay. The justices earlier Tuesday turned aside another Ferguson appeal.

Ferguson was convicted of killing eight people in South Florida in 1977 and 1978, and was a prime suspect in another double slaying. He suffers from paranoid schizophrenia but has previously been ruled competent for execution.

In Washington, the nation's high court order denying a stay noted that Chief Justice John Roberts took no part in the decision.

This month the Florida Supreme Court upheld a lower-court ruling based on testimony by a panel of psychiatrists appointed by Gov. Rick Scott that Ferguson is legally competent to be executed even though he suffers from paranoid schizophrenia.

The state justices wrote that "Ferguson understands what is taking place and why."

His lawyers argued, however, that Ferguson lacks rational understanding, because he suffers from delusions that he's the "prince of God" and that God is preparing him to return to Earth after his execution to save the United States from a communist plot.

In 1977, Ferguson and two accomplices fatally shot six people at a Carol City home, which at the time was the worst mass slaying in Miami-Dade County history. Even more shocking was Ferguson's murder of a teenage couple who had left a church event in Hialeah in 1978 with plans to meet friends for ice cream.

On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island. Credit: Newsday

Sarra Sounds Off, Ep. 15: LI's top basketball players On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island.

On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island. Credit: Newsday

Sarra Sounds Off, Ep. 15: LI's top basketball players On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island.

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