The Brief Two teens from Snohomish County were charged with assault in the first degree for the stabbing of a 17-year-old girl in West Seattle. Two teenagers from Snohomish County, accused of violently stabbing a 17-year-old girl, have been charged with assault using a deadly weapon. On Friday, the King County Prosecuting Attorney's Office charged the 17-year-old as an adult with first-degree assault. The Seattle Police Department said officers arrested both teen suspects in Marysville on July 8. Information in this story came from the Seattle Police Department and original FOX 13 Seattle reporting and interviews.