A Silverton teacher is facing charges for the alleged four-year sex abuse of a boy that began in 2002 when he was 13 years old. Susan Christina Alderson, 46, a sixth-grade teacher at Robert Frost Elementary School in Silverton, was arrested Tuesday after a search warrant was served on her home in the 2100 block of Robins Lane Southeast in Salem. Police believe Alderson maintained an ongoing sexual "relationship" with the now 19-year-old victim, who was not one of her students, said Lt. Steve Birr, criminal investigations section commander.