FORT MYERS, Fla. (AP) _ A man who already faces life sentences for three other rapes broke into a wide grin Saturday after a jury found him guilty in the kidnapping, rape and murder of a 12-year-old girl.

Robert Power, 29, also was found guilty of robbing Orange County deputy sheriff Richard Welty of his gun and radio in the field where Angeli Bare's body was found, hogtied and bleeding the day of her death.

The Lee County jurors took less than five hours to find Power guilty of first-degree murder in the Oct. 6, 1987, attack near Angeli's south Orange County home.

Prosecutors said they would emphasize Power's prison record in seeking the death penalty.

One of Power's attorneys, F. Wesley Blanker, said persuading the same jury next month to recommend a sentence of life in prison with no parole for 25 years will be unlikely.

Angeli's stepfather, Gary ''Butch'' Bare, was relieved by the verdict.

''It's a big hurdle in the grieving process,'' Bare said. ''It gives me somebody I can point my finger at and say 'you did it.' This was bad enough as it is, but it would be worse if the person who did it went free.''

Power, who already faces 10 consecutive life sentences in prison for rape convictions in Seminole and Osceola counties, blinked and then grinned immediately after the verdict was read.

''He doesn't look real upset,'' one juror said before the panel was escorted from the courtroom.

Blankner explained his client's reaction: ''Mr. Power was prepared for the worst in this situation. We didn't kid him. We knew it would be tough to convince a jury otherwise.''

Circuit Judge Gary Formet set the sentencing phase of the trial for sometime next month.

Power's attorneys hope that his prison record - he has spent all but two years of his adult life in jail - will help him.

''The jury will hear that he hasn't done well in the outside world,'' Blankner said. ''But he's demonstrated that he's done well in a controlled environment. He's been a model inmate.''

Blankner also said he will present evidence that Power was physically abused and sexually assaulted as a child.

Prosecutors, meanwhile, have said they will use Power's previous convictions and details of Angeli's slaying to try to persuade the jury to recommend death for Powers.

Power was convicted of raping two Kissimmee sisters, ages 12 and 16, and a Longwood woman, all within a month of Angeli's death. Formet barred prosecutors from using that evidence during the two-week trial, which was moved to Lee County because of publicity.

Angeli was found half-naked, hogtied and gagged in the field, bleeding from both the rape and a fatal stab wound in her neck. She had been punched in the face and her glasses were broken.

Welty identified Power from the witness stand as the man who stole his radio and gun. Radio parts, one bearing the same serial number as Welty's radio, were found in the house where Power was arrested eight days after the murder.

Blankner and Power's other attorney, Joerg Jaeger, said they will appeal. If Power is sentenced to death, the Florida Supreme Court will automatically hear the appeal.