MSNBC's 'MINDHUNTER' Premieres Sunday Nov. 30 At 10:00 PM ET

At any given time, there are an estimated 30-50 serial killers active in the United States. Former FBI Agent, John Douglas, knows them better than most. Renown as the architect of American criminal profiling, John Douglas knows that "the only way to truly understand the criminal mind is to get inside it." His approach is different from that of a journalist. Drawing on his 25 years of experience in the FBI's Behavioral Science unit, Douglas taps into the minds of the killers he interviews in order to find out who they are and what drove them to murder.

In "Mindhunter," premiering Sunday, November 30th at 10 P.M. ET, Douglas goes head-to-head with two of the nation's most disturbing and violent serial killers: Joseph Kondro and Donald Harvey.

Kondro is every parent's worst nightmare - a murderer who killed his friends' children. Harvey began his murderous lifestyle at age 18 as a hospital orderly. That year alone, he killed more people than most serial killers do in their entire lifetime. All of them were patients.

Douglas' discoveries have changed the nature of crime investigation. As a criminal profiler, his interviews have helped crime investigators create profiles that will more effectively identify and capture the serial killers among us.