By Eric M. Johnson

SEATTLE (Reuters) - Two fifth-grade boys are in custody in Washington state after they brought a knife and gun to school with the goal of killing a schoolmate in a foiled murder plot that shocked their rural town because of their youth, prosecutors said on Friday.

The boys, accused of conspiracy to commit first-degree murder despite their tender ages of 10 and 11, also planned to harm other students by luring them away one at a time, said Tim Rasmussen, a Stevens County prosecuting attorney.

The boys are due in court next week, where a judge will determine if they had the mental capacity to carry out the attack and if they can be prosecuted in juvenile court, which in Washington is typically reserved for older defendants between ages 12 and 18.

Prosecutors said the boys had boarded a school bus on their way to an elementary school in Colville, a city of 4,600 residents in the far northeast part of the state, with the 11-year-old in possession of a knife and the 10-year-old with a functional Remington Model 1911 semi-automatic handgun.

But a fourth-grade student riding the bus saw the knife and reported it to a teacher's aide, prosecutors said. School officials found the weapons before anyone was hurt, and the two boys were arrested. They are in a juvenile detention facility.

The boys sought to lure the girl away from school, where the older boy planned to stab her, prosecutors said.

"I was going to kill her with the knife and (the younger boy) was supposed to use the gun to keep anyone from trying to stop me or mess up our plan," the older boy told police, according to the declaration of probable cause filed in court.

They intended to kill the girl because "she's rude and always made fun of me and my friends," the younger boy told investigators, according to the documents.

Attorneys for the boys declined to comment. Continued...