Christopher Levins, 17, and Adam Sinclair, 19, were each booked Monday with one count of terrorizing — a felony punishable with up to 15 years in prison, Ascension Parish Sheriff Jeff Wiley said.
"This is not just a case of kids just talking to be cool," Wiley said. "These students had plans all worked out."
The alleged plot was discovered after an anonymous call was made to Dutchtown High School on Friday indicated some kind of armed disturbance was being planned. Levins and Sinclair admitted some of the planning but called it a "fantasy" and a joke, and said they never really planned to go through with it, Lt. Kevin Hanna said.
"At first of course, you don't want to believe it," principal Conrad Braud told CBS Radio News, "so I thought, yes, people had heard something but that it probably didn't have any, really, depth to the threats they had made."
Deputies said they found drawings and papers about the April 20, 1999, shootings at Columbine High in Littleton, Colorado. Students Eric Harris and Dylan Klebold killed 13 people before committing suicide. Twenty-three others were wounded.
Poems by the pair about being bullied and numerous writings in which Levins, a senior, and Sinclair, a sophomore, refer to themselves as "The Trenchcoat Mafia" were also found, authorities said. Harris and Klebold had been said to belong to a loosely knit group with that name at Columbine, though investigators later said they were not part of it.
"We found one drawing that had the student blowing the brains out of a particular teacher," Wiley said. Another depicted Levins and Sinclair on a school roof celebrating around dead bodies hanging out of windows, officers said.
"Some students had said they were planning some kind of harm to people at the school or the school facility itself," said Braud.
"Apparently, they were planning to wake up at 4:20 a.m. on April 20 of this year to do this," Maj. Tony Bacala said.
Authorities said no weapons were found, although detectives did find evidence that Levins and Sinclair had obtained information on buying shotguns and rifles.
The investigation is continuing and more arrests are possible, Wiley said. Neither student has a criminal record, and school officials said neither was a discipline problem.
"It's upsetting," said Braud.