A classmate of a teenager accused of murdering a teacher testified Friday that the boy showed her the handle of a handgun and bullets three days before the shooting.

Tiffany Jenkins said she didn't believe Nathaniel Brazill and another boy when they were talking on a street across from her house and claimed to have a gun. When she pressed them, Brazill pulled the gun partially from his pocket and showed her its handle and then the bullets, she said.

Jackson's testimony came one day after Brazill's jury watched, frame by frame, a grainy video surveillance tape of the boy pointing a gun at teacher Barry Grunow for four seconds before shooting him.

The key piece of evidence then shows Brazill, then 13, run down the hallway, point the gun at another teacher, then disappear out of the camera lens.

The defense maintains the May 26, 2000, shooting was an accident because the small "junk gun" went off unintentionally. Brazill had been sent home about two hours earlier for throwing a water balloon on the last day of school.

A video specialist hired by the prosecution walked the jury through the minutes-long video Thursday that showed the seventh-grader ride his bicycle into Lake Worth Middle School and with his arms outstretched, fatally shoot Grunow, his English teacher.

Specialist Grant Fredericks testified that Brazill, now 14, took a "shooter's stance" outside Grunow's classroom.

Fredericks said Brazill stood outside Grunow's classroom for 20 seconds and held his hands together, apparently pointing a gun at Grunow, for four seconds before shooting him.

The prosecution says Brazill deliberately killed Grunow because he was angry over a failing grade he was receiving from the teacher and because he was sent home early, although it was a school counselor who suspended him.

The defense says the teen pointed the .25-caliber semiautomatic pistol at Grunow to scare the teacher into letting him talk to two girls he liked in the classroom. Defense attorneys said Brazill thought the gun's safety was on.

The video also showed Brazill point the gun at math teacher John James as he fled down the hallway. Brazill is charged with aggravated assault with a firearm.

The video matches testimony from several students who said they saw Brazill pull a gun out of his pocket, point it at the teacher's head, pull back the slide and fire once.

Brazill faces life in prison with no parole if convicted of first-degree murder.

Earlier Thursday, one of Brazill's neighborhood acquaintances testified that the teen told him on the street the day of the shooting that he wanted to "f--- up" the school because he had been suspended for throwing water balloons.

Brandon Spann, 19, said he knew Brazill to be well behaved and that he didn't think anything else about their brief conversation.

Meanwhile, outside the courthouse, about 30 people protested the state's decision to try Brazill as an adult.

The state offered Brazill a deal calling for 25 years in prison in exchange for a guilty plea to second-degree murder, but Brazill and his family turned it down.

The trial, which began Monday, is expected to last about two weeks.