Broward County Judge Joel T. Lazarus imposed the mandatory sentence on Lionel Tate, calling his actions "cold, callous and indescribably cruel."

Tears rolled down Tate's face as his lawyer, his mother and several family friends asked the judge to reduce the first-degree murder conviction. But Lazarus said the trial was fair, the verdict just and that the sentence was mandated by law: "Incarceration for your natural life."

Defense attorney Jim Lewis said he would ask Florida Gov. Jeb Bush to commute Tate's sentence, and prosecutor Ken Padowitz said he would support the request. "This was a vicious, horrible murder. But I do not think that life is the appropriate sentence," Padowitz said.

Tate was just 12 years old when he beat 6-year-old Tiffany Eunick to death in July 1999. During the January trial, Lewis mounted a "blame-pro-wrestling" defense, in which he failed to persuade jurors that the boy -- who then weighed 166 pounds -- accidentally killed 48-pound Tiffany by imitating the actions of his television heroes.

An autopsy showed that Tiffany had suffered a fractured skull, a lacerated liver, a broken rib, internal hemorrhaging and other injuries that even medical experts called by the defense agreed were inconsistent with horseplay.

Bush on Friday said that he would not comment on a clemency petition until he sees it. But, he added: "It breaks my heart when we see these outbreaks of violence that just seem senseless -- whether it's in a school or, in this case, a child's home."

Bush were to turn down any appeal, Tate could be the youngest person in the nation ever sentenced to life in prison.

"Shame on the state of Florida," said Dan Macallair, vice president of the San Francisco-based Center on Juvenile and Criminal Justice. "This is something out of medieval times."

 Well before the January trial began, Lewis and Tate's mother, Kathleen Grossett-Tate, refused on several occasions an offer by Padowitz under which Lionel Tate would have served three years in a juvenile facility and 10 years of probation in exchange for a plea of guilty to second-degree murder.

Lazarus on Friday said that "the evidence of Lionel Tate's guilt is clear, obvious and indisputable. And that evidence supports the jury's verdict."

The judge said he found it "inconceivable" that the injuries Tiffany suffered could have been caused by replicating professional wrestling moves.

During the two-week trial, Lewis argued that Tate was unaware he was hurting Tiffany when he flung her around the room of his home as his mother -- a state highway patrol officer -- slept upstairs. He said Lionel spent hours watching "The Rock," Hulk Hogan and other wrestling stars on TV.

After finding Tate guilty, several jurors expressed regret that he was tried as an adult.

Since his conviction, several organizations have supported a lesser penalty -- including Amnesty International and the National Association for the Advancement of Colored People. (Tate is black, as was his victim.)

Prior to the sentencing, Lazarus said, he heard from dozens of people around the country -- most of whom urged him to show mercy.

"Most letters and calls refer to the victim only as an afterthought," Lazarus said Friday. "In the court of public opinion, Lionel Tate has turned into the victim.

"Tiffany Eunick will never have a second chance at life, and there are so many who plead for a second chance for the defendant," the judge said. "The acts of Lionel Tate were not the playful acts of a child. The acts of Lionel Tate were not the acts born out of immaturity."

Until the trial began, Grossett-Tate said, she had no idea her son could face life behind bars under Florida's mandatory sentencing law.

"People say I am a fool not to accept the plea from the state," she told Lazarus on Friday. "But how do you accept a plea for second-degree murder when your child was just playing?"

Jeffrey Butts, a senior research associate at the nonpartisan Urban Institute in Washington, D.C., said mandatory sentencing laws and a rise in violent crime by juveniles often can lead to startling outcomes. "We end up pushing the envelope on culpability and responsibility," Butts said.

"You can go back 100 years and find cases of kids being executed, but this raises the question of how far we're willing to go."