Detectives are slowly piecing together chilling clues from a series of brutal sexual assaults and murders across the country. Teenage girls are the target, and police are starting to question if one of their initial suspects was wrongfully convicted. As Jules Knox reports, a Mr. Big sting operation led officers to a second suspect who was hiding in plain sight.

For more than twenty years, Mark Mariani suffered from Crohn's disease. In the fall of 2010, he was told about medical advancements that brought renewed hope for a better quality of life. To celebrate he went to his favourite country bar. The following morning his family received a call from the police. Mark had been found dead in a northwest Calgary parking lot. Join senior crime reporter Nancy Hixt as she walks you through the trail of evidence police uncovered to learn how Mark Mariani came Face-to-Face with Evil.