Lee County Sheriff  Carmine Marceno showed evidence collected from two students' homes.
CNN  — 

Authorities in Lee County, Florida, thwarted a plot by two students to commit a school shooting, after a teacher shared a tip alleging a student had a gun in his book bag, according to Lee County Sheriff Carmine Marceno.

An 8th grade student at Harns Marsh Middle School in Lehigh Acres was removed from class and searched after the teacher shared the information with school officials, Marceno said at a news conference Thursday.

During the search, officials did not find any weapons, but did find a map of the school marked with the locations of “each of the school’s interior cameras,” said the sheriff.

Detectives from the department’s Youth Services Criminal Investigations division began an investigation and identified two male students, ages 13 and 14, who Marceno said were “involved in a plot to carry out a school shooting.”

The investigation uncovered the teens had taken an interest in the 1999 Columbine High school shooting and were “extensively studying to learn more about the incident and the shooters,” the sheriff continued,

“Detectives also learned that students were attempting to learn how to construct pipe bombs and how to purchase firearms on the black market,” Marceno said.

Search warrants executed at the students’ homes turned up “a gun and several knives,” among the evidence Marceno called “disturbing.”

Students at the school were “safe at all times” during the incident, Lee County School District Superintendent Ken Savage said.

“As soon as students reported the potential threat, the teacher notified administrators, who immediately brought in the school resource officer. Together they emptied the classroom and investigated,” Savage said.

Detectives interviewed both teens and “determined that they both met the criteria for evaluation at a mental health facility,” said Marceno.

The teens face charges of conspiracy to commit a mass shooting, according to the sheriff.

In the past, deputies have responded to calls at the homes of the teens “almost 80 times combined,” the sheriff said.

Marceno reiterated his department’s commitment to a zero-tolerance policy, saying, “Those responsible for threats, real or fake, will be held accountable.”

The teens will undergo a psychiatric evaluation under Florida’s Baker Act before being moved to a detention facility, a police spokesperson told CNN. The Baker Act allows mental health facilities to hold a person for up to 72 hours for evaluation.