Parents in the Shade-Central City School District said they were shocked that two students were arrested for allegedly planning a mass shooting at graduation.

State police arrested Jacob Deneen, 18, at Shade Junior-Senior High School on Tuesday.

Police say he confessed to planning a mass shooting at the school’s graduation along with two other juveniles.

A juvenile from the school district was taken into custody over the weekend.

Wednesday, the school district released a statement saying in part, “Given the circumstances and the serious nature of the situation, the two students will not be returning to Shade Junior Senior High School.”

The school statement also says, “Additional arrests could be forthcoming.”

Investigators said the other juveniles were overheard on Friday making plans for an attack. On Monday, state police said they were contacted by someone who said Deneen told him to ‘keep his children close and not send them to school.’ Deneen also allegedly said that another attack at the school was planned for this week.

Concerned parents told WTAJ they were surprised anything like this would happen in such a small community

“I’m very petrified for my kids. They’re only in the elementary, but one of them goes to the high school next year. I hope they get to the bottom of it,” said April Walls, a concerned parent.

Another parent, Kevin Twigg, said that his son, a junior at the high school, first told him about the arrests. Twigg said his son was shocked, but relieved.

“Once he found out this was a real threat, he was shocked but at the same time, like ‘wow that was close.’ said Twigg. “He said that [Deneen] was kind of normal. He never thought [Deneen] would do such a thing. He was a little upset because they seemed to be friends.”

Deneen is charged with making terroristic threats and risking a catastrophe. He’s being held at the Somerset County Jail.

State Police are still investigating the threat.

School officials said they will increase police presence at school buildings and on graduation day.

District Attorney Lisa Lazzari-Strasiser also told WTAJ that children need to understand the severity of making these threats, even as a joke.