True crime. Americans have become fascinated with the media genre in which actual crimes of real people are explored in depth. It is a shocking, new investigative documentary series that profiles some of history's most notorious mass murderers. This seven-part documentary series is filled with expert interviews and in-depth portraits of some of America's most infamous killers including John Wayne Gacy, David Berkowitz, Richard Ramirez, James DeAngelo, Aileen Wuornos, Jeffrey Dahmer, and others.