PLUMSTED — A New Egypt High School student who was arrested for plotting to "shoot up" the school's graduation was already facing charges for threatening another school's graduation, and was inspired by other mass shootings, according to court documents released Wednesday.

On Tuesday, the state Attorney General's Office announced that Matthew Vanderbeek, 19, would also be facing terrorism charges, which could result in a sentence of 30 years to life in prison. He was initially charged with third-degree terroristic threats and second-degree attempting to possess a firearm for an unlawful purpose.

The charging documents against Vanderbeek reveal a troubled young man who was obsessed with mass shootings, saying they gave him a "rush" that he had "never felt before."

Vanderbeek, who was arrested just days before the school graduation, in April had made a similar threat against Brick Township Vocational Technical School, where he was also a student, resulting in a nine-day suspension.  He was to be on home instruction for the rest of the year.

In his threat to "shoot up" the Brick school's graduation, he had said students should "wear orange to avoid him killing them," court records show.

After his most recent arrest, Vanderbeek told police he had "never mentioned graduation, and knew that a shooter would never give the date and time of his planned mass shooting," court documents show.

He said he studied mass shootings, including the one in Colorado in which James Holmes killed 12 people during a showing of "The Dark Knight" movie in 2012. Vanderbeek told police that he had dyed his hair the same color as Holmes' and had tried to have Holmes taken off death row so he could "speak to him to hear directly from Holmes his motivations for committing the murder."

Police searched Vanderbeek's home after the Brick threats and reported finding a bow and arrow.

After the subsequent New Egypt plot was revealed, they searched his room again and found a suicide note, entitled "SUICIDE NOTE," in which he apologized to his family.

New Egypt High School Principal Michael Mendes told police after his most recent arrest that Vanderbeek had been disappointed that authorities released him without sending him to jail after his first arrest.

Social Media Threats

After police learned about the threat against the Brick school and the plot to open fire at the New Egypt graduation, police interviewed students and staff at New Egypt to learn more about the two incidents. One of the students interviewed showed police a message he had sent to someone else stating that "aiden told me that matt vanderbeek is planning on shooting up the graduation n thst he has a gun lol."

New Egypt Principal Michael Mendes spoke to Michael Messinger, a student at the school, who heard from another person who was told by Vanderbeek of his plan. Mendes also told police he was aware of a video that Vanderbeek had posted on his Snapchat. The video, which was reviewed by police, showed part of the TV show "South Park" with a caption saying: "Where do you see yourself in 10 years." It showed characters armed with rifles and loading a gun. The video ends with a caption stating, "I see myself dead in the end."

Mendes also sent police a screen shot from Vanderbeek's Snapchat with a quote from the Bible about the end of the world and killing people.

Attempt to Buy a Gun

A student named Aiden Dupnak told police he was with Vanderbeek a week prior to his arrest. Dupnak told police that was when he noticed Vanderbeek had dyed his hair, and had asked him to drive him to Pinelands Sporting Goods in town to buy a gun. At that time Vanderbeek told Dupnak he planned to 'shoot up the school" on the day of graduation, according to court documents.

Dupnak told police he had told Vanderbeek that he would not drive him to the store and made Vanderbeek get out of the car. Dunpak told Messinger that he did not want to attend the graduation ceremony "for fear for his life, because he believed Matthew Vanderbeek might murder staff and students," court records show.

Vanderbeek is being represented by Public Defender Sheila Tobin.