A Washington teen has pleaded guilty to charges of planning a mass school shooting. Joshua O’Connor pleaded guilty on Thursday, December 6, 2018 to charges of first-degree attempted murder, first-degree robbery and possession of an explosive device. He was turned by his own grandmother, after she found violent journal entries in which the teen explained that he was “learning” from the mistakes of past shooters and bombers in preparation for his own plot.

School Shooting Averted In Washington

Joshua O’Connor is 18 years old. “We do believe that it was important for Mr. O’Connor to take responsibility for what he did and be held legally accountable for the steps that he took,” Andrew Alsdorf, Snohomish County deputy prosecutor told ABC News. When police raided O’Connor’s home, they found an AK-47 stored in a guitar case and inert grenades.

School Bus and Children

In line with the plea agreement, prosecutors dropped a weapons charge in connection to the attempted murder charge. The armed robbery charge that O’Connor pleaded guilty to relates to the robbery of a convenience store he committed prior to being arrested. O’Connor reportedly held up the store earlier the same week, wearing a mask and using his gun.

Turned In By Grandmother In February

O’Connor was arrested on February 14, 2018, the same day as the Parkland school shooting in which seventeen students and staff members of a Florida high school were murdered. He initially pleaded not guilty.

He has been in police custody since February, held on a $5 million bond. With his conviction in the books, O’Connor faces a maximum sentence of 28 years. His sentencing hearing has been scheduled for February 2019.

O’Connor’s grandmother, Catherine O’Connor, notified law enforcement officials of her grandson’s plan in February after reading his journal, in which the young man described a plot to carry out a school shooting at ACES Alternative High School. “What I’m reporting is I’m finding journal entries from my grandson,” Catherine O’Connor said, “and he’s planning on having a mass shooting at one of the high schools.”

Journal Entries Show Suspect Plotting Shooting

The violent journal entries show that O’Connor had entered the late stages of planning his shooting. “I’m preparing myself for the school shooting. I can’t wait. My aim has gotten much more accurate […] I can’t wait […] to blow all those [expletive] away,” the teenager wrote. “I need to make this shooting / bombing […] infamous. I need to get the biggest fatality number I possibly can. I need to make this count. I’m learning from past shooters / bombers mistakes, so I don’t make the same ones,” he continued.

A student of ACES Alternative High School, O’Connor writes in his journal that he left the decision of which school to carry out his massacre up to a coin flip. ACES “won” the flip, but Kamiak High School was also considered.

Would-Be School Shooter Purchased Supplies

O’Connor’s grandmother told officers that her grandson had recently bought inert grenades. Notes in his journal discuss how to add black powder to activate the bombs. He also considered the option of creating pressure cooker bombs, and discussed where to place them.

O’Connor was arrested at his high school shortly after his grandmother reported the journal entries to police. When searched, officers found marijuana and a knife. The teen was handcuffed and moved to the Everett Police Department, but managed to free himself from one of the handcuffs and ran off through the parking lot. He tripped and fell, but managed to “mule kick” one of the officers who ran to capture him.

There’s no way to know whether or not O’Connor would ever have actually carried out his murderous plans, according to Aaron Snell, Public Information Officer for the Everett Police Department, who spoke to KOMO. “We don’t know what the end result may have been or may not have been, but I think that the steps that were taken were the appropriate steps.”