Deborah Roberts sits down with the 20/20 team to unpack the shocking murder of Heidi Firkus. We reveal secret recordings from the killer’s wife that helped put him behind bars. Plus, hear a recent update in the case from the latest hearing. Could the guilty verdict be overturned? Listen to full episodes, including “Stranger in the House,” on the 20/20 Podcast feed. Stream 20/20 full episodes on Disney+ and Hulu under Season 48, episode 22. ––– Subscribe to ABC News on YouTube: https://abcnews.