20/20 Season 49 Episode 6 Footprints in the Snow

Juju Chang, co-anchor of "Nightline," reports on the mysterious murder of a 40-year-old mother near a popular ski resort. Identified as Ashley Schwalm, the mother of two and wife of a local firefighter was found inside a charred SUV. While her death was initially believed to be an accident, a forensic investigation revealed a more sinister end to her life. Friends and family in her town of Ontario were shocked to learn that Ashley's husband, a man who dedicated his life and career to helping those around him, used those skills to orchestrate an elaborate murder scheme. He also attempted to cover his tracks by creating an alibi built on technical footprints from phone records, text messages and even his own home-surveillance footage. It wasn't until eagle-eyed detectives deconstructed his alibi that they were able to capture a killer.