Oregon HS Student Accused of Attempted Murder in Alleged Bomb Plot

May 25, 2013— -- An Oregon high school student has been accused of plotting a school bomb attack "specifically modeled" after the Columbine shooting, prosecutors said today.

The student at West Albany High School allegedly hid at least six bombs and bomb-making material in a secret compartment under the floor of his bedroom, Benton County District Attorney John Haroldson said.

Grant Acord, 17, was arrested late Thursday at his home on two counts of possession of a destructive device and two counts of manufacture of a destructive device, according to the Albany Police Department.

But Haroldson said today that Acord will be charged as an adult with attempted aggravated murder. He is expected to be arraigned Tuesday in Benton County Circuit Court, the prosecutor said.

"The charge of attempted aggravated murder requires that we prove that a substantial step was taken toward the completion of the crime," he said. "In this case, we would be relying upon evidence of plan. Diagrams, checklists, a plan to use explosive devices and firearms to carry out a plan specifically modeled after the Columbine shootings."

According to Haroldson, the explosives police allegedly found included pipe bombs, Molotov cocktails, napalm bombs and explosives made from drain cleaner.

The school was allegedly chosen because it was a "target-rich environment," the district attorney said.

"I can't say enough about how lucky we are that there was an intervention," the district attorney said. "When I look at the evidence in the case, I shudder to think of what could have happened here."

He would not say when the teen allegedly planned to carry out the attack.

"That said there were also some indications that it could happen at any time, too," Haroldson said. "So you have -- A -- the methodical planning and then -- B -- I suppose he could get really excited about it and go early."

Police were alerted to the case by a tip that Acord had made a bomb and planned to target his high school, accord to a statement from the Albany Police Department.

"This is beyond a kid playing with a couple of cherry bombs. It was serious enough to warrant calling out the bomb squad," Albany police Capt. Eric Carter told ABC affiliate KATU-TV in Portland.

"This went above and beyond teenage curiosity," he said.

The Associated Press contributed to this report.