In 1997, a 16-year-old girl named Brianna Stewart showed up at Evergreen High School in Vancouver, claiming to be a runaway who had been taken in by a local family. She enrolled in school and did a bunch of normal teenage things, like joining the tennis team, and going with a boyfriend to the high school dance. Except Brianna was actually 28-year-old Treva Throneberry. And Throneberry had been posing as a teenager in a variety of cities for ten years.
When her ruse was finally discovered, she was charged with defrauding the Vancouver school system for more than $19,000. Though DNA tests confirmed that Stewart is actually Throneberry, she still refused to admit the truth. She was sentenced to three years in jail and served two.
She was released in 2003 and continues to maintain that she is Brianna Stewart.