The boy left school at about 1:30 p.m. with his mother, but returned to the bridge over 6200 South at 2700 West that links to the school's campus just as classes were getting out, Hoyal said. There, he met up with some other students and produced a handgun just before shooting himself.
Police determined that the gun came from a locked safe in the boy's home. He knew where the gun was and somehow gained access to it, Hoyal said in a Friday news release.
The Salt Lake Tribune does not normally report on suicides, but makes an exception when the death occurs in a very public manner.
Hoyal said the students who witnessed the shooting were being questioned by investigators. It is still unclear where the student was able to obtain the gun.
Granite School District Spokesman Ben Horsley said the student shot himself in front of witnesses that included fellow students and parents.
"The district is greatly concerned with respect to the individuals who may have witnessed this," Horsley said.
The 911 call came in at about 3:05 p.m.
By 8 p.m., throngs of students, friends and their parents returned to the bridge, where two shrines of flowers, candles and stuffed animals had been set up to honor the teen's memory. Huddled in tight groups and packing the bridge, they embraced each other, prayed together and consoled one another. Once the vigil started moving from the crowded bridge to one of the junior high fields, six balloons were released skyward that's where their lost classmate is now, students said through tears.
"He was one of the sweetest guys I've ever known," said Hunter Evensen, a fellow ninth-grader. He remembered when the teen had bought him a drink and never expected to be paid back for it.
But other students picked on him, Evensen said. His classmates and friends said he was bullied and called names at school.
Ninth-grader Marcus Hansen never saw the bullying himself, but he heard other students talking about the teen behind his back.
"I hated when people [bullied him]. I felt so bad for him," said Kaleb King, who is in the same grade. King hopes that people learn not to judge and bully other people the way they did his classmate.
Grief counselors and other members of the district's crisis team were on hand in the school's cafeteria to speak with students, family and any other members of the public, Horsley said.
The crisis team also will be at Bennion Junior High and Calvin Smith Elementary School on Friday, according to a statement from the district.
"We're here to educate our kids and provide them with a bright future ... it's a tragedy when [that's cut short]," Horsley said.