Police say several powerful bombs were discovered in the bedroom of Grant Alan Accord, a 17-year-old junior at West Albany High School. NBC's Mike Taibbi reports.

An Oregon high school student accused of hatching a Columbine-style bomb plot was charged Tuesday as an adult with attempted murder and possession of a destructive device.

Grant Acord, 17, was ordered held on a $2 million bail. He was not physically present, but appeared in court via closed-circuit television from a secure location, according to Reuters.

Acord did not enter a plea deal and was ordered back to court on June 4.

His mother said he suffers from a rare form of obsessive-compulsive disorder caused by childhood infections.

Authorities said the devices found in his possession included pipe bombs, Molotov cocktails, a Drano bomb and a napalm bomb.

The devices were found under floorboards in his bedroom, prosecutors said. West Albany High School, which is about 75 miles south of Portland, was swept for explosives and none were found.

In a statement issued through a lawyer Monday, Marianne Fox, Acord’s mother, indicated that Grant had Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS), a type of OCD typically triggered by strep throat or scarlet fever.

Parents of affected kids describe sudden, explosive changes in behavior, with normally mild-mannered children becoming agitated, even violent.

“My heart goes out to everyone affected by Grant's struggle with PANDAS, a rare form of OCD,” the statement said.

“I grieve for my son, but understand and support the efforts of law enforcement to keep our beloved community safe. This is a challenging and confusing time for everyone who knows Grant. I will have no further comment while I wait with the rest of you to see what unfolds.”

Acord was arrested Thursday night after a 911 caller said he was planning to blow up the school, police said. Prosecutors said that in addition to the bombs, investigators found a checklist and timeline for the alleged attack.

The plot was "specifically modeled" on Columbine — the 1999 massacre in Colorado in which two students murdered 12 schoolmates and a teacher, said Benton County District Attorney John Haroldson.

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

Students were set to return to West Albany for the first time since the arrest.

"I have been advised that none of the evidence developed thus far suggests any broader conspiracy or involvement by any other persons," school superintendent Maria Delapoer said in a letter to parents, according to the Albany Democrat-Herald.

"The bottom line is that the school is safe and that students can return to school on Tuesday confident that no outstanding threats remain."

Police said they would have extra security on hand to quell any fears.

The Associated Press contributed to this article

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