In early August 2009, a young man named Mats - who lived in Falun, Sweden - called the police in desperation. He reported that his fiancée Linda Chen had gone missing. She'd left the house on a Saturday evening wearing the shoes she planned to wear for her wedding, but had never returned home. At first the police didn't take the investigation particularly seriously - since a missing person isn't necessarily a police issue. But a suspicion was raised a month later - when Mats also disappeared. The case shone a spotlight on how the killer is often close to home.