HOUSTON -- It wasn't your average Thursday at Splendora High School after a former student was arrested for threatening to shoot up the school.
"It's always a school administrator's worst nightmare to have a notification of that type," said Dr. Genese Bell, superintendent at Splendora ISD.
Splendora ISD Police said Jacob Marino had dark intentions and he posted them online on Facebook, allegedly writing, "At this point I'm seriously contemplating a school shooting. I want to kill everyone in Splendora High ... especially the staff."
Peggy, a parent at Splendora High, says posts like this are no joke.
"Chills, my heart raced," she said. "I wanted to go to the school and pick up my daughter right then and there."
"It's a scary thought, especially when you see what's happened elsewhere and the Columbine anniversary is coming up," said Peggy.
The school district acted fast. A current and former student alerted them to the threat Wednesday night. Police tracked Marino to his home where he lives with his parents. He admitted to making the threat and was arrested.
"Any threat involving a weapon, a bomb or a shooting is taken seriously," said Bell.
Weeks ago, Marino allegedly shared a photo that read, "Everyday I contemplate the idea of becoming a serial killer." He commented, "Yeah so true."
More police were on campus Thursday, even after the arrest. The district said it was just a precaution.
“You don’t have the opportunity to say this is a joke," said Bell.
No one answered the door at Marino's home, but neighbors described the 18-year-old as a loner. They said they're relieved no one took this as a joke.
"People may think he wouldn't do it, but I mean all the signs were there, and nobody would have done anything, then he would have done it, so it's a good thing they did something," said neighbor Raymond Pennington."
Marino is facing making a terroristic threat charges. That's a 3rd-degree felony. He is being held in the Montgomery County Jail on a $75,000 bond.