Nurse Charles Cullen is one of America's most prolific serial killers. Police say he may have murdered up to 400 victims, Cullen claimed he acted mercifully. An in-depth look into the case reveals the truth behind his motives.
Genres: Crime , Documentary
Keywords: betrayal , breaking-point , female-killer , forensic-evidence , homicide , homicide-detective , homicide-investigation , interview , killer , murder , murder-investigation , murder-suspect , murder-victim , re-creation , reenactment , true-crime