Trailer: 20/20 ’The Killer Down the Hall’ - Premieres Oct. 4th on ABC

One of the most sensational true crime stories. A brutal murder and a shocking twist. 20/20 ‘The Killer Down the Hall’ premieres Friday, Oct. 4th at 9/8c on ABC Network. Stream on Hulu. Subscribe to ABC News on YouTube: ABC News is your daily source of breaking national and world news, exclusive interviews and 24/7 live streaming coverage. Download the ABC News app for the latest headlines and alerts: Watch 24/7 coverage of breaking news and live events on ABC News Live: Watch full episodes of World News Tonight with David Muir here: Read ABC News reports online: ABC News is the home to the #1 evening newscast “World News Tonight with David Muir,“ “Good Morning America,” “20/20,” “Nightline,” “This Week” with Georg