Jurors in the case of Nathaniel Brazill could believe the 14-year-old never meant to harm the popular teacher he is on trial for killing. They could conclude that Barry Grunow's death was an accident, that Brazill didn't intend to pull the trigger on the gun that ended his favorite teacher's life.

But even then, Brazill could go to prison for life without parole for first-degree murder.

How jurors in highly publicized case rule on small details could mean the difference between Brazill being set free again one day or spending the rest of his life behind bars. In this case, it may come down to whether or not a school is considered a public place.

The crucial moments for Brazill may come Monday morning, when prosecutors and defense attorneys will begin their closing statements. Later that day, they will have to decide whether Brazill, who has confessed to pulling the trigger last May 26, is guilty of first-degree murder, second-degree murder or manslaughter.

Even within the first-degree murder charge, there is leeway for a variety of findings by the jury. The charge includes not only premeditated murder but felony murder, murder committed in the course of another felony. Either way, a first-degree murder charge means Brazill would get a mandatory sentence of life without parole.

But whether Brazill was committing another felony when he shot Grunow is in dispute. Brazill fired the gun while they were standing in the doorway of Grunow's classroom in Lake Worth Middle School. He'd returned to the school to say goodbye to two friends before summer break after being suspended and sent home for throwing a water balloon.

Brazill testified he got mad when Grunow didn't take him seriously when he asked to talk to the two girls privately. The teen said he pointed the .25-caliber pistol at the teacher and pulled back the hammer to scare Grunow into letting them into the hallway. Brazill testified that the gun, which he pointed at Grunow's head for four seconds, went off unintentionally.

The state argues that because Brazill had been kicked off campus, he was committing burglary when he came back. If the jury agrees, Brazill could be convicted of murder even if the jury also decides that he only wanted to threaten Grunow, not kill him.

Defense attorney Robert Udell says that under Florida law, Brazill did not commit burglary because a school campus is a public place.

Brazill's parents admitted Friday that their son should serve time in the shooting death of his 35-year-old English teacher, but said they believe he committed manslaughter, which carries a maximum 15-year sentence.

"This was reckless abandonment of a firearm," said Brazill's father, also named Nathaniel Brazill.

But prosecutor Marc Shiner has worked throughout the trial to provide jurors evidence that Brazill's intent was darker than the Udell would have it.

In his cross-examination of Brazill, Shiner had the teen show jurors how he held the palm-sized handgun and pulled back its slide, putting a bullet in the chamber.

"You wanted to make sure a live round was in there?" Shiner asked.

"Yes."

"That was why you pulled the slide back, prior to shooting a man between the eyes, right?"

"Yes."

Defense attorney Robert Udell has insisted Brazill didn't plan to shoot or threaten Grunow., and an excused juror in the trial agreed from what he'd heard and seen.

Alternate juror Kenneth Wright of Delray Beach said he believed the boy thought the gun's safety was on when he pointed the loaded pistol at the teacher and probably didn't know how much pressure was needed to pull the trigger.

Wright, excused Wednesday after the defense rested, said he believed Brazill was guilty of second-degree murder, which carries a sentence of 25 years to life.

One of Grunow's brothers wasn't buying it. He said Brazill deliberately killed the teacher and should spend the rest of his life in prison.

"If this isn't first-degree murder, I don't know what is," Steve Grunow said. "He said he was going to do it, he did it."