Teacher Barry Grunow arrives at Lake Worth Middle School for work.

Nathaniel Brazill leaves Grunow's first period language arts class. Being the last day of school, Grunow treats them to a video of the movie Killing Mister Griffin.

At some point in the morning, Brazill poses with Grunow, reportedly his favorite teacher for a photo. He also gives his crush, Dinora Rosales, a card.

Lunch period. Students report balloons sticking out of Brazill's pockets and warn others that Brazill is going to attack them with water balloons later that afternoon.

Brazill returns with other students to Room 301, Grunow's classroom.

Brazill attends band class with teacher Frank Bermudez without incident.

During the five-minute break between classes, Brazill is seen filling up balloons with water.

A water balloon fight breaks out in a school corridor between about a dozen students. The students scatter when word spreads that guidance counselor Kevin Hinds was on his way to break it up. Hinds catches Brazill and fellow student Michelle Cordovaz with balloons.

Grunow begins teaching his final class.

Hinds takes Brazill and Cordovaz to the office of assistant principal Bob Hatcher, who decides not to suspend them but to send them home early instead. Hinds calls Brazill's mother, Polly Powell, to pick up her son from school. Powell says she is at work and can't pick up him up, but asks that Brazill be allowed to walk to his grandmother's house to get his house keys.

Hinds escorts Brazill and Cordovaz to the front hallway and watches as they leave school grounds.

As Brazill and Cordovaz walk from the school, Brazill tells her that he has a gun and that he plans on returning to the school and shooting Hinds, Cordovaz later told police. "I just kinda laughed at it because I didn't think he'd do it," she said.

After Brazill and Cordovaz go their separate ways, Brazill runs into 18-year-old neighbor Brandon Spann and asks to borrow a gun but to no avail. He hops a ride with a delivery man to a pizzeria and walks home from there. With the door locked, Brazill walks to his grandmother's obtains the key and goes home.

From his house, he retrieves a "Saturday Night Special," a loaded .25 caliber Raven semiautomatic pistol he had stolen a week earlier from family friend Elmore McCray, whom Brazill often referred to as his grandfather. He rides his bicycle back towards the school, stopping at his aunt's house on the way.

Brazill re-enters through the back door of the school and heads for Room 301, Grunow's classroom. He demands Grunow allow him to speak to students Dinora Rosales and Vonae Ware, but according to witness accounts, Grunow smiled and told him to go back to class.

Brazill pulled the loaded pistol from his pocket and pointed it at Grunow. Grunow tells him to stop pointing the gun at him and to put the gun away. One bullet strikes Grunow in the face and he collapses.

As Brazill flees down the hall, he allegedly points the gun at math teacher John James — who came out of his classroom to investigate the shots — and threatens him. Brazill flees the building through the rear door of another classroom, but surrenders to a police officer outside the school.