An autopsy shows that a woman found dead in a burning house in Washington's San Juan Islands died of multiple stab wounds.
KOMO-TV says a medical examiner made that finding in the death of 49-year-old Sharon Hammel of Friday Harbor.
A 15-year-old boy has been arrested for investigation of murder and arson.
Fire broke out at Hammel’s home just after 2 a.m. Sunday. At the time, KOMO says the woman, her teenage son and a tenant were in the home. The boy and tenant managed to escape.
Additional details were not immediately available late Thursday.
The federal Bureau of Alcohol, Tobacco, Firearms and Explosives is assisting in the investigation, as is the State Patrol Crime Lab.