The 13-year-old Eatonville Middle School student is now locked up at Tacoma's Juvenile Detention Center after the disturbing discovery. Police say another student found a kill list, allegedly written by the teenager, containing the names of 10 classmates.
On Friday, the Eatonville School District alerted parents about the list, which targeted other boys.
"It's shock and outrage, of course - nobody wants to hear that," says parent Brandy Hawes.
Eatonville Mayor Ray Harper says no weapons were involved, and police arrested the student at school on Friday.
"There was a reason he did this, and that reason needs to be found out," says Harper.
Police are saying nothing about a possible motive. But one of the first questions parents are asking is: did this involve bullying?
"If he was bullied, this is what drives kids. They're kids. Their brains aren't functioning all like mine and yours," says parent Michelle Garcia.
But an Eatonville school teacher who did not want to speak on camera told KOMO News she sincerely doubts the bullying theory.
"I know all of those boys on that list," she said. "Not a single one of them is a bully. The few I've talked to say they have no idea why they'd be on a kill list."
Still, that's not a comfort to some who feel these kinds of things happen in bigger cities - far away.
"I think it's different in a small town, because we're all family pretty much," says Hawes. "It's a close-knit community. It feels more close to home."
The Pierce County Prosecutor is still deciding about possible charges. One possibility is a charge of felony harrassment, which carries a possible penalty of two years locked in a juvenile detention center.
The district told parents the student is on emergency expulsion, and there is no threat to the school. Classes will begin as usual Monday morning.