A high-school senior named Hae Min Lee disappeared one day after school in 1999, in Baltimore County, Maryland. A month later, her body was found in a city park. And two weeks after that, her former boyfriend and classmate, 17-year-old Adnan Syed, was arrested for the crime. He was convicted, and sentenced to life in prison. Syed has always said he had nothing to do with Lee’s death.