DUMONT, N.J. -- (UPDATE) While one family deals with the unthinkable, other parents of Dumont High School students were grateful that what had been a terrifying ordeal ended with their children returning safely to them.
Authorities said they seized a rifle from the home of a sophomore who was taken into custody Monday after allegedly threatening a mass shooting.
"It was a long gun, a rifle," a ranking law enforcement official told Daily Voice. "It was not his.
"His mother was extremely cooperative," the official added. "[The gun] was at the house. He didn't bring it to the school."
"Dumont definitely did everything right today, and all of the families are hugging their kids tighter for what might have been," one mother said Monday night.
At the same time, she said, "one family is going to suffer terribly....They're a very close family. This is going to rock their world and make this kid an outcast."
The 800-student high school was first locked down near the end of lunch, after district officials said Dumont police got a call from a nearby police department about an online threat.
"The threat just simply stated something to the effect of someone was going to shoot up the school," Police Chief Michael Conner said.
A Bergen County Regional SWAT team responded along with Dumont police, officers from other towns (including Haworth, Bergenfield and New Milford) and county sheriff's officers.
"They had to search the entire school for the kid because nobody was in their next period class yet, since lunch wasn’t technically over," said the mother, who was in touch with her daughter throughout the ordeal.
The 15-year-old boy eventually was found and brought to police headquarters, authorities said.
School officials suspended him pending the results of an investigation by the Bergen County Prosecutor's Office, the lead law enforcement agency in the case.
The incident began just before noon.
"Half the kids were in the school when it happened, half were still outside," the mother said. "They were never evacuated."
The complete lockdown continued until about 2:15 p.m., when the students were escorted into the gym and "wanded," she said.
"They never went to classes in the afternoon. School didn’t resume as normal," the mother noted.
Attendance was taken of the students inside and outside the school before they were dismissed around 4 p.m., she said.
"Obviously it was very intimidating because their guns were huge and the SWAT team is intimidating," the mother said, "but they were nice to the kids."
A heightened police presence will be at the school on Tuesday, authorities said.
Click here to sign up for Daily Voice's free daily emails and news alerts.