COLVILLE, Wash. (AP) — Court documents released Wednesday gave chilling details about the plans of two fifth-graders from Colville to kill a girl classmate and possibly others on the day they were caught with a knife and gun in school last week.

The Spokesman-Review reported that the boys, ages 10 and 11, remained in custody on charges of conspiracy to commit first-degree murder, tampering with a witness and conspiracy to possess a firearm after they were arrested last Thursday.

Under Washington law, children ages 8 to 12 are presumed not to have the mental capacity to form the intent to commit crime.

But Deputy Prosecutor Lech Radzimski will present court records to a judge on Feb. 20 to try to show why law enforcement officials believe they have enough evidence to overcome that presumption.

Authorities discovered the plan when a fourth-grader came forward and told a school employee. Colville police officers then arrived at Fort Colville Elementary School and began questioning the boys, who admitted the plot and gave details about how they were going to kill a girl in their class, according to court records.

A detective stood with the boys as they waited for transport to a juvenile hall when he overheard one of the boys tell the other: "If I find out who told them about our weapons I'm going to kill them. I don't care when I get out of jail I'm going to come back and kill them," court records said.

The case began on the bus ride to school. A fourth-grade boy saw one of the boys playing with a knife.

As soon as the bus arrived at school about 7:45 a.m., the boy approached school employee Richard Payette and told him what he saw on the bu s.

Payette asked the 11-year-old suspect whether he had a knife. The boy "denied any knowledge of the knife" and a search of his backpack came up empty, records showed.

But a teacher suggested that Payette search the 10-year-old's backpack because he was with the 11-year-old on the bus. Payette searched the second boy's backpack and found a knife, a .45 caliber semi-automatic pistol and a full ammunition clip, court records showed.

A different staff member then asked the 10-year-old why he had the gun. The boy said he and the 11-year-old were going to "get" a girl identified in court documents only by initials.

"When asked what he meant by get" her, (the 10-year-old) responded that he and (the 11-year-old) were going to get (the girl) away from the school and do her in," court records said. The 10-year-old "further stated that the (11-year-old) was going to stab (the girl) with a knife and (the 10-year-old) was supposed to keep everyone away."