One-and-done killers have exposed massive shortcomings in the world of profiling. What makes these offenders so impossible to pin down, and what is the future of profiling in light of these previously overlooked murderers?    To follow the Unraveled investigations even further, stream the specials exclusively on discovery+. Go to discoveryplus.com/unraveled to start your 7-day free trial today. Terms apply. See acast.com/privacy for privacy and opt-out information.