Wuornos' last words: 'I'll be back'

STARKE, Florida (CNN) -- Saying she'd be back, serial killer Aileen Wuornos was executed by lethal injection Wednesday at the Florida State Prison in Starke.

Wuornos was pronounced dead at 9:47 a.m. ET, said Sterling Ivey, a spokesman for the Florida Department of Corrections.

Wuornos, called "The Highway Hooker" and "The Damsel of Death," admitted she killed six middle-aged men in 1989 and 1990, luring some of them by posing as a stranded motorist on north central Florida highways.

Florida state attorney John Tanner, who prosecuted the Wuornos case, said after watching the execution that Wuornos' actions were "not much different from the present killer in the D.C. area."

"She killed seven men in cold blood," said Tanner. "She didn't premeditate the individual killing. She had a pattern, and she took targets of opportunity ... just whoever happened in her path on the day that she decided to kill."

The Wuornos case was the subject of books, movies and even an opera. In time, she apologized to her victims' families. But last year -- after a decade on death row -- Wuornos volunteered for the death penalty, saying she would kill again.

"There is no point in sparing me," she said in July 2001. "It's a waste of taxpayers' money."

Wuornos' bizarre final statement was a mix of religion and science fiction:

"I'd just like to say I'm sailing with the Rock and I'll be back like 'Independence Day' with Jesus, June 6, like the movie, big mother ship and all. I'll be back," Wuornos said.

"I'd just like to say I'm sailing with the Rock and I'll be back like 'Independence Day' with Jesus, June 6, like the movie, big mother ship and all. I'll be back." "I'd just like to say I'm sailing with the Rock and I'll be back like 'Independence Day' with Jesus, June 6, like the movie, big mother ship and all. I'll be back." -- Wuornos' final statement

Police said Wuornos, 46, was a prostitute who worked the Florida highways when she gained notoriety as a female serial killer.

Sgt. Bob Kelley of the Volusia County Sheriff's Department -- who investigated the killing of Wuornos' first victim, Richard Mallory -- said Wuornos shot her victims to death, robbed them and then dumped their bodies.

At first, she claimed she acted in self-defense.

"After she was convicted of the first murder of Richard Mallory, she then pled guilty to the others, and after a certain point in time she started to recant and say she wasn't a victim," Kelley said. "She simply robbed and killed those men to gain their personal property and to gain money."

When she asked to be put to death, Wuornos said the same thing.

"I killed those men, robbed them as cold as ice. And I'd do it again, too," Wuornos said. "There's no chance in keeping me alive or anything, because I'd kill again. I have hate crawling through my system."

Wuornos stood trial only for the killing of Mallory; she pleaded no contest to five other killings. And police believe she was responsible for the death of a seventh man, but his body was never found and Wuornos was not charged in his death.

Recently, as the execution date drew near, a defense attorney raised questions about whether Wuornos was mentally competent to demand her own death by lethal injection. But Wuornos insisted she knew what she was doing.

State Attorney John Tanner witnessed the execution Wednesday.

"I am so sick of hearing this 'she's crazy' stuff," she said. "I've been evaluated so many times. I'm competent, sane, and I'm trying to tell the truth, and I'll take a polygraph on every single word on those pages."

After examining Wuornos, a panel of three psychiatrists ruled her competent for execution and Florida Gov. Jeb Bush agreed.

Wuornos said last week during a final psychiatric evaluation she was ready to die because she was "tired of lying," Tanner said.

"I believe her spiritual conversion had something to do with it," he said. "She said she knew she was being executed for the killing of six men, but that she had actually killed a seventh."

Tanner, who watched the execution, said he prayed for Wuornos, "for all the victims and for all of us" as he watched.

"This is a tough business," he said. "But I think it's necessary."

-- CNN Correspondent John Zarrella contributed to this report.