Nathaniel Brazill, now 14, moved his man-sized frame with the awkward movements of a boy as he shuffled to the witness stand Thursday to beg for mercy from the judge who will sentence him for the murder of Barry Grunow, his seventh-grade English teacher.

"I wished it had not happened and I could bring Mr. Grunow back," Brazill said, breathing heavily and staring out at the victim's family with wide, dry eyes. "If I'd thought about what had happened this would never have happened. To Mr. Grunow's family, I'm sorry. And regardless of what anyone thinks, I never intended to hurt Mr. Grunow."

Brazill faces a minimum of 25 years without parole and a maximum of life in prison when he is sentenced Friday by Palm Beach County Circuit Court Judge Richard Wennet. The sentencing will be broadcast live on Court TV at 11:30 a.m.

The case has drawn national attention because of Brazill's young age — he was just 13 when he shot and killed the popular Lake Worth, Fla., teacher on the last day of school last year. The crime, which shocked those who knew Brazill was not a troubled student, has once again raised the debate on how society should treat such a young killer.

"Why does a young person make such a choice?" asked Pam Grunow, the teacher's widow and now a single mother of two young children, her voice softly quavering and her eyes holding back tears. Unlike other members of the teacher's family, the widow did not ask Judge Wennet to give Brazill the maximum penalty.

"I do not know what price Nathaniel should pay for taking Barry's life, because that is not my job," she said. "I do not have the wisdom and I do not feel I can be objective. I just hope as a society that we can create some good out of the sad loss of this public servant and of the great guy that I loved."

The victim's mother was more direct, pleading with the judge to send Brazill away for life.

"We have heard from [defense lawyer Robert Udell] and others about what a good person Nathaniel Brazill was," Phyllis Grunow said. "I don't think good people steal a gun, aim it at people, and kill them. This was not an accident. I think Nathaniel should be punished to the fullest extent of the law."

A good student with little history of disciplinary problems, Brazill pulled a gun on Grunow, shot and killed him in a classroom doorway on May 26, 2000, the last day of classes for Lake Worth Middle School.

Prosecutor Marc Shiner claimed the shooting was premeditated, the result of a "storm brewing inside Nathaniel Brazill" that turned into a torrent of violence after the teen was kicked out of school on the day of the shooting for throwing water balloons.

The defense said Brazill had a crush on a girl at school and, upset that he would not get a chance to see her before summer vacation, returned after his suspension with a gun in order to force Grunow to let her out of class. Udell, the defense lawyer, told the jury that the boy pulled the trigger accidentally during a tense standoff with his teacher.

Almost a year to the date of the shooting, on May 16, a Palm Beach County jury convicted the teen of second-degree murder.

Udell called a series of witnesses, including experts in child development and psychology, during Thursday's sentencing hearing to make some sense of how Brazill could have ended up shooting one of his favorite teachers.

Domestic violence, never discussed at home, may have had some impact on the boy, one expert testified.

"Nathaniel not only witnessed but participated in some of the violence in order to rescue his mother from (her boyfriend's) physical abuse," said Dr. Janet Stevenson, a child psychologist who interviewed the Brazill family extensively. "[Brazill's mother] did not indicate any conversations with her son about these troubling aspects."

"You know, I don't see how he's that much different except he held an awful lot inside. He was bubbling, and the judgment was way off," Jacqueline Patterson, an education expert who talked to Brazill in prison, slowly said, choosing her words carefully and lingering over their implications as she looked out at the the courtroom audience. "The signs weren't apparent at school and there was no one on watch at home."

The boy's mother, Polly Powell, sobbed as she took the stand Thursday to ask the judge for leniency. She tried to explain how her son could have killed his teacher, and she also accepted part of the blame.

"Judge Wennet, Nate is my first born and I love him like nobody else can. I just ask you please have mercy on him," Powell cried. "We know that he did something wrong and we know he must be punished. But if you have kids you know you raise them the best you can and you try to provide for them. I don't know what happened with my baby."

"If what happened was partly the result of something I did, then I take responsibility for that," Powell said, forcing the words out through sobs, her voice rising to a mournful crescendo.

The judge will have to weigh Powell's statement against damaging testimony earlier Thursday from prosecution witnesses who described a remorseless Nate Brazill.

"There were two very different sides to him, the public side everybody saw in the courtroom and the side we saw behind closed doors," recalled Lt. Mark Chamberlain. "The day of opening statements, before we brought Brazill up he asked us if the jury was seated, and we said no, and he said good, because when they go into the courtroom I'm going to go like this," said the officer, mimicking how Brazill stuck out his index fingers and moved his thumbs as if firing twin pistols.

Detective Steven Venetucci also took the stand and spoke about two letters Brazill wrote from prison, neither one of which was admissible during the trial. In one of the notes, the boy told a friend to get him a gun for when he gets out of jail.

Shiner referenced the officers' testimony several times during closing arguments for the hearing, when he asked Judge Wennet to impose the maximum sentence on the boy.

"This young man deserves to spend the rest of his life in jail without parole. That's the only way we can insure he'll never hurt another person again," the prosecutor said.

Udell, Brazill's attorney, had the last word and asked for the minimum of 25 years.

"Life means life. He will never see the outside of a prison. If that's the only way we can ensure the public safety then nothing in these courts means a thing," Udell said. "If that's the only way, then we're just warehousing people. Someday he has to be given the chance to take his place back in society, and we ask you to impose a 25-year sentence."