Police arrested a 17-year-old West Albany High School student Thursday for plotting a Columbine-style attack on his school using explosive devices.

Authorities learned of the incident after someone called police and said Grant Acord was planning to blow up the high school when students returned from the Memorial Day weekend, CNN reports.

When police arrested Acord, they found six types of explosives, as well as checklists and a diagram for the alleged attack. The following day, authorities recovered napalm, pipe and drain cleaner bombs, as well as Molotov cocktails from a secret compartment in the boy's room.

On the night Acord was arrested, police searched the high school for bombs. Before students returned to class, Oregon state police also conducted a search with sniffer dogs.

Meanwhile, Acord's mother said the teen suffers from a rare form of obsessive compulsive disorder (OCD), called PANDAS, which stands for pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. This type of OCD is triggered by strep throat or scarlet fever and often causes sudden, explosive changes in behavior, which children becoming agitated and even violent.

Acord will be charged as an adult with attempted aggravated murder. Additionally, he faces bomb-making charges and unlawful possession of a deadly weapon with intent to use against another person.