No one was hurt, thanks in part to a fourth-grader who saw one of the boys playing with a knife on a school bus Thursday morning and told a school worker, Stevens County Prosecutor Tim Rasmussen said.
"These young men conspired to kill," Rasmussen told The Spokesman-Review (http://is.gd/eZ1rEW). "It was interrupted by the bravery of a fourth-grader who saw something and said something - and interrupted a murder."
The Fort Colville Elementary School students, aged 10 and 11, were taken into custody Thursday morning after a search showed a knife and handgun in one boy's backpack.
They're expected to be formally charged in juvenile court with conspiracy to commit first-degree murder, possession of a firearm and witness tampering, the newspaper reported.
Police interviews showed the boys intended to use the weapons Thursday, Rasmussen said.
Colville School District Superintendent Michael Cashion said he was told the boys "had a plan to kill an ex-girlfriend - I don't know what a girlfriend means in fifth grade - and harm other students.
"There was no list, but names were given to the police," he said. "I can't get my mind around it."
A deputy prosecutor asked Superior Court Judge Al Nielson to order that the boys have no contact with eight children identified only by their initials.
All the alleged targets were fifth-grade classmates, school Principal Clayton Allen said.
The two boys were expelled, as was a third boy who reportedly knew about the plan but agreed to stay silent in return for the promise of $80.
The newspaper said much of the probable cause evidence has not been made public yet.
The judge scheduled a Feb. 20 hearing to determine whether the boys had the capacity to form the intent to commit a crime. Children ages 8 to 12 are presumed not to have that capacity unless prosecutors can show evidence that the children tried to keep the crime secret, displayed similar conduct in the past, and knew what they were doing was wrong, Deputy Prosecutor Lech Radzimski said.
The alleged plot evolved over two weeks, Radzimski said.
Allen has been meeting with concerned parents.
"I don't know how I would have dealt with it if a kid had been killed," he said. "It's tough."