POLK COUNTY, Fla. (WFLA) — A 15-year-old was accused of bringing a gun to Tenoroc High School in Lakeland, along with a magazine full of a dozen rounds, that cannot be traced, authorities said.

“A ghost gun is one that’s put together with parts that don’t have serial numbers and our suspect refused to tell us where the gun came from,” said Polk County Sheriff Grady Judd.

According to the sheriff’s office, the teen brought the gun to school to show his friends and wanted to shoot it in the woods after school.

But, the sheriff said, things escalated during an argument in the bathroom.

“He threatened a student in the bathroom with it,” Judd said. “As a result, he picked up a felony aggravated assault. The student said ‘I was clearly scared.’”

A different student told a school resource deputy about the gun being on campus, which is how law enforcement got involved.

“No one was injured. We recovered a gun. The system worked and a student saw something and said something,” Judd added.

News Channel 8 is not including the name of the suspect, due to his age.

He is facing several felony charges including possession of a firearm on a school campus, carrying a concealed firearm, aggravated assault with a deadly weapon, and disruption of a school function.

“Pay more attention to your kids than you usually do because that’s when you’re gonna notice they’re acting different, acting weird,” said Luis Torres, a parent.

According to Polk County Public Schools, this is the first known incident involving a firearm on campus this school year.

In August, the district started random bag checks at different schools every day.

“It’s extremely concerning when a student brings a weapon to school, and PCPS works with our law enforcement partners to ensure that there are severe consequences for these incidents… We will continue to evaluate our security procedures and work with our law enforcement partners to keep our campuses as safe as possible,” wrote a school district spokesperson in a statement.

Sheriff Judd, with a stern warning, said people who bring weapons to school will be criminally charged.

“It’s very important that parents coach up their kids and tell them, no guns, no knives at school. It not only will get you in trouble with school administration but it’s zero tolerance with the sheriff’s office and law enforcement agencies,” he said.