Published: Oct 08, 2012 12:04 PM EDT

TALLAHASSEE, Fla. (AP) - The Florida Supreme Court says a judge properly denied a mental competency hearing for a convicted mass killer scheduled for execution on Oct. 16.
    
The justices unanimously denied an appeal Monday from 64-year-old John Errol Ferguson.
    
Circuit Judge Nushin Sayfie of Miami acknowledged Ferguson "undoubtedly suffers from mental illness" but ruled he waited too long to ask for a clemency hearing.
    
The high court agreed in an unsigned opinion. It rejected other issues raised by Ferguson's lawyers after finding they, too, were untimely filed.
    
Ferguson was convicted of killing six people in a 1977 drug-related, execution-style mass killing in Carol City, a Miami suburb. He also was convicted of killing two Hialeah teenagers on their way to a church meeting in 1978.

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