Season 1, Episode 9 - Most Shocking Killers: Original air date: 10/13/2013. Any time best friends turn on each other, it's a tragedy--years of love and trust swept away in a moment of anger, jealousy, or greed. But some cases are so shocking that nobody sees them coming. These are the seven least likely suspects from Season One of I Killed My BFF. Narrated in the voice of murder victim Misti Mayo, this special episode traces the stories of seven killers who fooled everyone... until it was too late. Check out I Killed My BFF for more videos and extras!