Updated at 5:25 p.m.

A 14-year-old boy plotted to kill his parents by drugging them with sleeping pills supplied by a 13-year-old friend, then setting fire to their Albany home, authorities say. Both teens have been arrested.

The boys are accused of attempted aggravated murder and attempted arson. They remained held Tuesday at the Linn-Benton Juvenile Detention Center. Neither child has been identified by the Benton County Sheriff's Office.

The boys will not be charged as adults, said Benton County Chief Deputy District Attorney Ryan Joslin. Measure 11, an Oregon law that sets mandatory minimum sentences for serious crimes, doesn't apply in this case because the boys are younger than 15.

Attempted aggravated murder is among the list of Measure 11 crimes in the state, for example, and carries a mandatory minimum sentence of 10 years in prison.

At least six kids heard discussions about the 14-year-old planning to commit some act of violence, according to Benton County Undersheriff Greg Ridler. A child told an adult, who told the father of the 14-year-old, who called police Thursday and reported learning of his son's alleged plans, Ridler said.

The 14-year-old was arrested Saturday and his friend was arrested Monday after he admitted to providing the sleeping pills and knowing of the other boy's plans, Ridler said. The 13-year-old got the pills from home and gave them to his friend last Tuesday, according to Ridler.

The motive for killing the parents is not immediately clear, Ridler said.

No other arrests are expected in the case because it doesn't appear anyone else had detailed knowledge of what the 14-year-old boy was allegedly planning, the undersheriff said.

"Eventually the information got to us and thankfully we were able to investigate this before anything happened," Ridler said, "but we really want to impress on kids that if they hear any information about other kids planning to commit violent acts, let their parents know and inform law enforcement."

"It's better that we are informed and allowed to determine whether there is any truth to the threats rather than not," he said.

The Benton County Sheriff's Office asks anyone with more information on this case to contact them at 541-766-6858.

Juveniles can also report other suspicious activity anonymously to Safe Oregon, a program that allows people to report suspected threats privately, at 844-472-3367 or tip@safeoregon.com.

-- Everton Bailey Jr.

ebailey@oregonian.com

503-221-8343; @EvertonBailey